

| Acronym | Sense | Language | Topics | 
|---|---|---|---|
| U | Uridine | In English | → Genetics → Biochemistry, biophysics | 
| U | Uranio = U | Uranium | In French = U | Uran | In Tosk = U | يورانيوم | In French = U | Uran | In Azerbaijani = U | Уран | In Belarusian = U | Уран | In Bulgarian = U | ইউরেনিয়াম | In Bengali = U | Uranijum | In Bosnian = U | Urani | In Catalan = U | Uraniu | In Corsican = U | Uran | In Czech = U | Uran | In Danish = U | Uran | In German = U | Ουράνιο | In Greek = U | Uranium | In English = U | Uranio | In Spanish = U | Uraan | In Estonian = U | Uranio | In Basque = U | اورانیوم | In Persian = U | Uraani | In Finnish = U | Urani | In Friulian = U | Uranio | In Galician = U | אורניום | In Hebrew = U | Uranij | In Croatian = U | Iranyòm | In Haitian Creole = U | Urán | In Hungarian = U | Ուրան (տարր) | In Armenian = U | Uranium | In Indonesian = U | Uranio | In Ido = U | Úran | In Icelandic = U | Uranio | In Italian = U | ウラン | In Japanese = U | jinmrvurani | In Lojban = U | ಯುರೇನಿಯಮ್ | In Kannada = U | 우라늄 | In Korean = U | Uranium | In Latin = U | Uran | In Letzeburgesh = U | Uranas | In Lithuanian = U | Urāns | In Latvian = U | യുറേനിയം | In Malayalam = U | Ilhuicateōtepoztli | En Nahuatl = U | Uran | In Low German = U | Uranium | In Dutch = U | Uran | In Nynorsk = U | Uran | In Norwegian = U | Uran | In Polish = U | Urânio | In Portuguese = U | Uranyu | In Quechua = U | Uraniu | In Romanian = U | Уран | In Russian = U | यूरानियम | In Sanskrit = U | Uraniu | In Sicilian = U | Uranijum | In Serbo-Croatian = U | Urán | In Slovak = U | Uran | In Slovenian = U | Urani | In Albanian = U | Уранијум | In Serbian = U | Uran | In Swedish = U | Urani | In Swahili = U | யுரேனியம் | In Tamil = U | ยูเรเนียม | In Thai = U | Uranyo | In Tagalog = U | Uranyum | In Turkish = U | Уран | In Ukrainian = U | Urani | In Vietnamese = U | 鈾 | In Chinese | In Esperanto | → Chemistry | 
| U | Uranium = (look above) | In French | → Chemistry | 
| U | Uran = (look above) | In Tosk | → Chemistry | 
| U | يورانيوم = (look above) | In French | → Chemistry | 
| U | Uran = (look above) | In Azerbaijani | → Chemistry | 
| U | Уран = (look above) | In Belarusian | → Chemistry | 
| U | Уран = (look above) | In Bulgarian | → Chemistry | 
| U | ইউরেনিয়াম = (look above) | In Bengali | → Chemistry | 
| U | Uranijum = (look above) | In Bosnian | → Chemistry | 
| U | Urani = (look above) | In Catalan | → Chemistry | 
| U | Uraniu = (look above) | In Corsican | → Chemistry | 
| U | Uran = (look above) | In Czech | → Chemistry | 
| U | Uran = (look above) | In Danish | → Chemistry | 
| U | Uran = (look above) | In German | → Chemistry | 
| U | Ουράνιο = (look above) | In Greek | → Chemistry | 
| U | Uranium = (look above) | In English | → Chemistry | 
| U | Uranio = (look above) | In Spanish | → Chemistry | 
| U | Uraan = (look above) | In Estonian | → Chemistry | 
| U | Uranio = (look above) | In Basque | → Chemistry | 
| U | اورانیوم = (look above) | In Persian | → Chemistry | 
| U | Uraani = (look above) | In Finnish | → Chemistry | 
| U | Urani = (look above) | In Friulian | → Chemistry | 
| U | Uranio = (look above) | In Galician | → Chemistry | 
| U | אורניום = (look above) | In Hebrew | → Chemistry | 
| U | Uranij = (look above) | In Croatian | → Chemistry | 
| U | Iranyòm = (look above) | In Haitian Creole | → Chemistry | 
| U | Urán = (look above) | In Hungarian | → Chemistry | 
| U | Ուրան (տարր) = (look above) | In Armenian | → Chemistry | 
| U | Uranium = (look above) | In Indonesian | → Chemistry | 
| U | Uranio = (look above) | In Ido | → Chemistry | 
| U | Úran = (look above) | In Icelandic | → Chemistry | 
| U | Uranio = (look above) | In Italian | → Chemistry | 
| U | ウラン = (look above) | In Japanese | → Chemistry | 
| U | jinmrvurani = (look above) | In Lojban | → Chemistry | 
| U | ಯುರೇನಿಯಮ್ = (look above) | In Kannada | → Chemistry | 
| U | 우라늄 = (look above) | In Korean | → Chemistry | 
| U | Uranium = (look above) | In Latin | → Chemistry | 
| U | Uran = (look above) | In Letzeburgesh | → Chemistry | 
| U | Uranas = (look above) | In Lithuanian | → Chemistry | 
| U | Urāns = (look above) | In Latvian | → Chemistry | 
| U | യുറേനിയം = (look above) | In Malayalam | → Chemistry | 
| U | Ilhuicateōtepoztli = (look above) | En Nahuatl | → Chemistry | 
| U | Uran = (look above) | In Low German | → Chemistry | 
| U | Uranium = (look above) | In Dutch | → Chemistry | 
| U | Uran = (look above) | In Nynorsk | → Chemistry | 
| U | Uran = (look above) | In Norwegian | → Chemistry | 
| U | Uran = (look above) | In Polish | → Chemistry | 
| U | Urânio = (look above) | In Portuguese | → Chemistry | 
| U | Uranyu = (look above) | In Quechua | → Chemistry | 
| U | Uraniu = (look above) | In Romanian | → Chemistry | 
| U | Уран = (look above) | In Russian | → Chemistry | 
| U | यूरानियम = (look above) | In Sanskrit | → Chemistry | 
| U | Uraniu = (look above) | In Sicilian | → Chemistry | 
| U | Uranijum = (look above) | In Serbo-Croatian | → Chemistry | 
| U | Urán = (look above) | In Slovak | → Chemistry | 
| U | Uran = (look above) | In Slovenian | → Chemistry | 
| U | Urani = (look above) | In Albanian | → Chemistry | 
| U | Уранијум = (look above) | In Serbian | → Chemistry | 
| U | Uran = (look above) | In Swedish | → Chemistry | 
| U | Urani = (look above) | In Swahili | → Chemistry | 
| U | யுரேனியம் = (look above) | In Tamil | → Chemistry | 
| U | ยูเรเนียม = (look above) | In Thai | → Chemistry | 
| U | Uranyo = (look above) | In Tagalog | → Chemistry | 
| U | Uranyum = (look above) | In Turkish | → Chemistry | 
| U | Уран = (look above) | In Ukrainian | → Chemistry | 
| U | Urani = (look above) | In Vietnamese | → Chemistry | 
| U | 鈾 = (look above) | In Chinese | → Chemistry | 
| U&E | Usability & Ergonomie | In English | → Human-computer interaction | 
| U2R | Union des Républicains Radicaux | In French | → Political parties and movements | 
| U3M | Université du Troisième Millénaire | In French | → Higher education, universities | 
| U3P | Union pour la Promotion de la Propulsion Photonique (www.u3p.net) | In French | → Organizations and associations → Astronautics | 
| UA | Urban Anthropology | In English | → Serial publications, periodicals → Anthropology → Sociology | 
| UA | Union des Anarchistes | In French | → Organizations and associations → Anarchist organizations | 
| UA | Uniform Allowance | In English | → Military affairs | 
| UA | Union Anarchiste | In French | → Organizations and associations → Anarchist organizations | 
| UA | Urgence Absolue | In French | → Traumatology | 
| UAB | Uždara akcinė bendrovė | In Lithuanian | → Economics | 
| UAC | Union Anarchiste Communiste | In French | → Anarchist organizations → Communist parties | 
| UACR | Union Anarchiste Communiste Révolutionnaire | In French | → Anarchist organizations → Communist parties | 
| UAD | User Accommodation Document | In English | |
| UAE | Université Abdelmalek Essadi (www.uae.ma) | In French | → Higher education, universities → Morocco | 
| UAE | Union des Avocats Européens (www.uae.lu) | In French | → Organizations and associations → Law, jurisprudence → Europe | 
| UAE | Unité d'Accueil et d'Écoute | In French | |
| UAE | United Arab Emirates | In English | → Geography | 
| UAE | Union des Auto-Entrepreneurs (www.union-auto-entrepreneurs.com) | In French | → Organizations and associations → Economics → Labour, labour economics | 
| UAEA | Uluslararası Atom Enerji Ajansı (www.iaea.org) = IAAE | Internacia Agentejo pri Atom-Energio | In Esperanto = IAEA | International Atomic Energy Agency | In English = AIEA | Agence Internationale de l'Énergie Atomique | In French = AIEA | Agenţia Internaţională pentru Energie Atomică | In Romanian = МААЕ | Международна агенция за атомна енергия | In Bulgarian = AIEA | Agència Internacional de l'Energia Atòmica | In Catalan = MAAE | Mezinárodní agentura pro atomovou energii | In Czech = IAEA | Det Internationale Atomenergiagentur | In Danish = IAEO | Internationale Atomenergieorganisation | In German = OIEA | Organismo Internacional de Energía Atómica | In Spanish = סבא"א | הסוכנות הבינלאומית לאנרגיה אטומית | In Hebrew = IAEA | International Atomenergie Agence | In Letzeburgesh = AIEA | Agenzia Internazionale per l'Energia Atomica | In Italian = IAEA | अंतर्राष्ट्रीय परमाणु ऊर्जा अधिकरण | In Hindi = MAAE | Меѓународна агенција за атомска енергија | In Macedonian = МАГАТЭ | Международное агентство по атомной энергии | In Russian = AIEA | Agência Internacional de Energia Atómica | In Portuguese = MAEA | Międzynarodowa Agencja Energii Atomowej | In Polish = МАГАТЕ | Міжнародне агентство з атомної енергії | In Ukrainian = IAEA | สำนักงานพลังงานปรมาณูระหว่างประเทศ | In Thai = EANA | Energia Atomikoaren Nazioarteko Agentzia | In Basque | In Turkish | → International relations → Energy economics → Nuclear technology | 
| uAEM | Universities Allied for Essential Medicines | In English | → Higher education, universities → Medicine | 
| UAIC | Universitatea Alexandru Ioan Cuza (www.uaic.ro) | In Romanian | → Higher education, universities | 
| UAJ | Ural-Altaische Jahrbücher | In German | → Serial publications, periodicals → Language, linguistics, literature → Geography, biography, history | 
| UAL | United Airlines (https://www.united.com) | In English | → Transport by air → United States | 
| UALE | Universala Artista Ligo de Esperantistoj | In Esperanto | → Organizations and associations → Arts → Artificial languages (linguistics) | 
| UAM | Universidad Autónoma de Madrid (www.uam.es) | In Spanish | → Higher education, universities → Spain | 
| UAM | Universidad Autónoma Metropolitana (www.uam.mx) | In Spanish | → Higher education, universities → Mexico | 
| UAM | Uniwersytet im. Adama Mickiewicza (www.amu.edu.pl) | In Polish | → Higher education, universities → Poland | 
| UAM | User Authentification Module | In English | → Software | 
| UAM | Unité d'Appui Multimédia | In French | → Computer science → Document processing | 
| UAM | Universidad Autónoma de Manizales (www.autonoma.edu.co) | In Spanish | → Higher education, universities | 
| UAM | University Art Museum | In English | → Museums → Higher education, universities → Arts | 
| UAM | United Adult Ministries | In English | → Christianity | 
| UAMI | Ufficio per l'Armonizzazione nel Mercato Interno (http://oami.europa.eu) = OHIM | Office for Harmonization in the Internal Market | In English = OHMI | Oficina per a l'Harmonització del Mercat Interior | In Catalan = HABM | Harmonisierungsamt für den Binnenmarkt | In German = OAMI | Oficina de Armonización del Mercado Interior | In Spanish = OHMI | Office de l'Harmonisation dans le Marché Intérieur | In French = IHMI | Instituto de Harmonização do Mercado Interno | In Portuguese | In Italian | → European Union → Industrial property → Artistic property → Europe | 
| UAMS | University of Antwerp Management School | In English | → Higher education, universities → Management → Belgium | 
| UAOD | The United Ancient Order Of Druids | In English | → Organizations and associations → Modern spiritual movements | 
| UAPET | Updates in Applied Physics and Electrical Technology | In English | → Serial publications, periodicals → Engineering, technology → Electrical engineering | 
| UAPM | Uniunea Artiştilor Plastici din Republica Moldova | In Romanian | → Organizations and associations → Plastic arts | 
| UAPV | Université d'Avignon et des Pays de Vaucluse | In French | → Higher education, universities | 
| UAR | Upper Austrian Research (https://www.uar.at/) | In English | → Research institutes → Research policy → Engineering, technology → Austria | 
| UARS | Upper Atmosphere Research Satellite | In English | → Meteorology, climatology → Astronautics | 
| UART | Universal Asynchronous Receiver Transmitter | In English | → Telecommunications | 
| UART | Universal Asynchronous Receiver-Transmitter | In English | → Data → Networks, communication | 
| UAS | Urban Aboriginal Strategy | In English | → Regional planning | 
| UAS | Union des Anarcho-Syndicalistes | In French | → Anarchist organizations | 
| UASER | Ultrasound Amplification by Stimulated Emission of Radiation | In English | → Engineering, technology → Acoustics | 
| UAT | Union Aéromaritime de Transport | In French | → Transport and postal services | 
| UAW | United Auto Workers | In English | → Organizations and associations → Labour, labour economics → Automobile manufacturing | 
| UB | Unité Bethesda | In French | → Diagnostics → Blood and circulatory system → Immunology and allergy | 
| UB | Utility Bridge | In English | → Civil engineering → Construction | 
| UB | Universiteitsbibliotheek | In Dutch | → Libraries → Higher education, universities | 
| UB | Unité de Brillance | In French | → Lighting, illumination engineering | 
| UB | Universitat de Barcelona (https://www.ub.edu) | In Catalan | → Higher education, universities → Spain | 
| UBA | Umweltbundesamt | In German | → Central administration → Threats to the environment | 
| UBAA | University at Buffalo Alumni Association (www.alumni.buffalo.edu) | In English | → Associations → Higher education, universities | 
| UBB | Universitatea Babes-Bolyai (www.ubbcluj.ro) | In Romanian | → Higher education, universities | 
| UBCNA | Union Belge Contre les Nuisances des Avions | In French | → Organizations and associations → Transport and postal services | 
| UBE | Université Bouddhique Européenne (www.bouddhisme-universite.org) | In French | → Education → Buddhism | 
| UBE | Uluslararası Bilgisayar Enstitüsü | In Turkish | → Computer science → Higher education, universities | 
| UBE | University at Buffalo Experience | In English | → Higher education, universities | 
| UBER | Undetected Bit Error Rate | In English | → Computer science | 
| UBF | Union Bouddhiste de France | In French | → Organizations and associations → Buddhism → France | 
| UBF | University of Buffalo Foundation (http://ubfoundation.buffalo.edu) | In English | → Foundations → Higher education, universities | 
| UBF | Unique Brand Factory (www.ubf.com.tr) | In English | → Advertising | 
| UBMD | University at Buffalo Medical Doctor | In English | → Higher education, universities → Medicine | 
| UBO | Université de Bretagne Occidentale (www.univ-brest.fr) | In French | → Higher education, universities → France | 
| UBP | Université Blaise Pascal | In French | → Higher education, universities | 
| UBR | Unspecified Bit-Rate | In English | → Computer science | 
| UBS | Université de Bretagne-Sud (www.univ-ubs.fr) | In French | → Higher education, universities → France | 
| UBS | Union de Banques Suisses (www.ubs.com) | In French | → Banks → Switzerland | 
| UC | Unitat Catalana | In Catalan | → Political parties and movements | 
| UC | Unité de Conditionnement | In French | |
| UC | Unité de Compte | In French | → Finance | 
| UC | Unsatisfactory Condition | In English | → Quality management | 
| UC | Ulcerative Colitis | In English | → Pathology | 
| UC3M | Universidad Carlos III de Madrid (www.uc3m.es) | In Spanish | → Higher education, universities → Spain | 
| UCA | Uniform Chart of Accounts | In English | |
| UCAF | Universal Cardholder Authentication Field | In English | → Computer-based techniques → Electronics | 
| UCAFR | Universitas Comeniana Acta Facultatis Rerum Naturalium Physica | In Latin | → Serial publications, periodicals → Physics | 
| UCAP | Union de la Communauté Algérienne de Paris (www.ucap-association.com) | In French | → Organizations and associations → France | 
| UCAR | Unsatisfactory Condition Action Report | In English | → Quality management | 
| UCB | Union du Crédit pour le Bâtiment | In French | → Banks → Construction → France | 
| UCBL | Université Claude Bernard Lyon 1 | In French | → Higher education, universities → France | 
| UCBRP | Union pour la Coopération Bourgogne/Rhénanie-Palatinat | In French | → Organizations and associations → International relations | 
| UCC | Uniform Code Council | In English | → Organizations and associations | 
| UCC | Universal Checkout Console | In English | → Computer hardware → Human-computer interaction | 
| UCC | Uniform Commercial Code | In English | → Trade | 
| UCCA | Unione Circoli Cinematografici Arci (www.ucca.it) | In Italian | → Organizations and associations → Cinema, movies → Italia | 
| UCD | Urine Collection Device | In English | → Environmental technology, water supply, waste management | 
| UCDDU | Union Compagnonnique des Devoirs Unis | In French | → Organizations and associations → Labour, labour economics | 
| UCE | Unsolicited Commercial Email | In English | → Networks, communication → Telecommunications | 
| UCE | Union des Candidats Émergents | In French | → Political parties and movements | 
| UCEC | Universal Content Extented Classification | In English | → Computer science | 
| UCESG | Union du Corps Enseignant Secondaire Genevois | In French | → Organizations and associations → Education | 
| UCH | Ubiquitin Carboxy-terminal Hydrolase | In English | → Enzymes | 
| UCI | Union Cycliste Internationale (www.uci.ch) | In French | → Organizations and associations → Sport, physical exercises | 
| UCI | Union des Constructeurs Immobiliers | In French | → Organizations and associations → Construction | 
| UCI | University Community Initiative | In English | → Higher education, universities | 
| UCIJ | Uni(e)s Contre une Immigration Jetable | In French | → Organizations and associations → Migrations | 
| UCJG | Unions Chrétiennes de Jeunes Gens | In French | → Organizations and associations → Christianity | 
| UCKG | Universal Church of the Kingdom of God = EURD | Église Universelle du Royaume de Dieu | In French = IURD | Iglesia Universal del Reino de Dios | In Spanish = IURD | Igreja Universal do Reino de Deus | In Portuguese | In English | → Christianity → Modern spiritual movements | 
| UCL | University College London (https://www.ucl.ac.uk) | In English | → Higher education, universities → United Kingdom | 
| UCL | Université Catholique de Louvain | In French | → Roman catholic church → Higher education, universities | 
| UCLA | University of California, Los Angeles (www.ucla.edu) | In English | → Higher education, universities → United States | 
| UCLAP | University of California Los Angeles - Astronomical Papers | In English | → Serial publications, periodicals → Astronomy → United States | 
| UCLAT | Unité de Coordination de la Lutte Anti-Terroriste | In French | → Public administration, government | 
| UCLM | Universidad de Castilla la Mancha | In Spanish | → Higher education, universities | 
| UCM | Union de Classes Moyennes | In French | → Organizations and associations → Labour, labour economics | 
| UCM | Universidad Complutense de Madrid (www.ucm.es) | In Spanish | → Higher education, universities → Spain | 
| UCMF | Union des Compositeurs de Musiques de Films (www.ucmf.fr) | In French | → Organizations and associations → Music → Cinema, movies → France | 
| UCN | Uniform Control Number | In English | |
| UCN | Unité Comptable Nationale | In French | → Accounting | 
| UCODEP | Unity and Cooperation for Development of People | In English | → Organizations and associations → Development | 
| UCPTE | Union pour la Coordination de la Production et du Transport d'Électricité | In French | → Organizations and associations → Electrical engineering | 
| UCR | Unsatisfactory Condition Report | In English | → Quality management | 
| UCRAM | Unité de Coordination et de Recherches Anti-Mafia | In French | → Police | 
| UCRE | Unité de Coordination des Ressources en Eau | In French | → Hydrology | 
| UCS | Universal Character Set | In English | → Writing systems → Data | 
| UCS | Universal Control System | In English | |
| UCS | Utilities Control System | In English | |
| UCS | Unité Communale de Santé | In French | → Medicine | 
| UCSC | University of California at Santa Cruz (https://www.ucsc.edu/) | In English | → Higher education, universities → United States | 
| UCSEI | Ufficio Centrale Studenti Esteri in Italia | In Italian | → Organizations and associations → Higher education, universities → Italia | 
| UCSG | Universidad Católica Santiago de Guayaquil | In Spanish | → Roman catholic church → Higher education, universities | 
| UCTA | Urine Collection Transfer Assembly | In English | → Environmental technology, water supply, waste management | 
| UCV | Union du Commerce de Centre-Ville | In French | → Organizations and associations → Trade | 
| UCW | Understanding Children's Work and its Impact | In English | → Organizations and associations → Labour, labour economics → Fundamental rights | 
| UD | Utile Dulci | In Latin | → Organizations and associations → Sport, physical exercises | 
| UDA | Union Des Annonceurs | In French | → Organizations and associations → 659 | 
| UDA | Université d'Auvergne (www.u-clermont1.fr) | In French | → Higher education, universities → France | 
| UDA | User-Developed Application | In English | → Software | 
| UDB | Update Buffer | In English | |
| UDC | Universal Decimal Classification = UDK | Universala Dekuma Klasifiko | In Esperanto = CDU | Classification Décimale Universelle | In French = UDC | Universele Decimale Classificatie | In Dutch = CDU | Clasificación Decimal Universal | In Spanish = UDC | Universel Decimal Classifikation | In Danish | In English | → Libraries |