| NASTRAN | NASA Structural Analysis Program | In English | → Spaceflight engineering, astronautics |
| NAT | Nonconformance Action Team | In English | |
| NATF | Naval Air Test Facility | In English | → Aerodynamics → Aeronautics, aircraft |
| NatH | Natural History | In English | → Serial publications, periodicals → Biological sciences |
| NATMA | Nonlinear Analysis Theory Methods Applications | In English | → Serial publications, periodicals → Analysis |
| NATO | North Atlantic Treaty Organisation (www.nato.int) = OTAN | Organització del Tractat de l'Atlàntic Nord | In Catalan = OTAN | Organizazión d'o Tratau de l'Atlantico Norte | In Aragonese = OTAN | Organización del Tratáu del Atlánticu Norte | In Asturian = AFNA | Aozadur Feur-emglev Norzh-Atlantel | In Breton = OTAN | Organisation du Traité de l'Atlantique Nord | In French = ন্যাটো | উত্তর আটলান্টিক নিরাপত্তা জোট | In Bengali = NATO | Οργανισμός Βορειοατλαντικού Συμφώνου | In Greek = NATO | Nordatlantikvertrag-Organisation | In German = OTAN | Organización del Tratado del Atlántico Norte | In Spanish = NATO | Nord-Atlantika Traktat-Organizo | In Esperanto = NAFO | Noard-Atlantyske Ferdrachsorganisaasje | In Frisian = OTAN | Organización do Tratado do Atlántico Norte | In Galician = ნატო | ჩრდილოატლანტიკური თანამშრომლობის ორგანიზაცია | In Georgian = OTAN | Organização do Tratado do Atlântico Norte | In Portuguese = OTNA | Organizaciya le Tratatosko le Nordutne Atlantikosko | In Vlax Romani = OTAN | Organizaţia Tratatului Atlanticului de Nord | In Romanian = NATO | Organisatschoon vun den Noordatlantikverdrag | In Low German |
In English | → International relations |
| NatPh | Nature Physics | In English | → Serial publications, periodicals → Mathematics and natural sciences |
| NATSA | North American Taiwan Studies Association | In English | → Associations → Language, linguistics, literature → Geography, biography, history |
| Natur | Nature | In English | → Serial publications, periodicals → Mathematics and natural sciences |
| NAUI | National Association of Underwater Instructors | In English | → Associations → Education |
| NAVA | North American Vexillological Association (www.nava.org) | In English | → Associations → 9299 |
| NAVAID | Navigation Aid | In English | → Vehicle engineering |
| NAVCA | North American Veterinary College Administrators | In English | → Organizations and associations → Veterinary medicine |
| NAVDAD | Navigational Derived Air Data | In English | → Aeronautics, aircraft |
| NAVSAT | Navigation Satellite | In English | → Spaceflight engineering, astronautics → Transport and postal services |
| NAVT | NASA Altimeter Verification Telemetry | In English | → Spaceflight engineering, astronautics |
| NAWIRA | North America West Indies Rugby Association | In English | → Associations → Football and rugby |
| NAYC | National Association of Youth Clubs | In English | → Associations |
| NAYDP | National Arts & Youth Demonstration Project | In English | → Education → Arts |
| NB | Narrow Band | In English | → Telecommunications |
| NB | Navigation Base | In English | |
| NB | National Body | In English | |
| NBA | NSTS Berthing Adapter | In English | |
| NBA | Narrow-Band Amplifier | In English | → Telecommunications |
| NBDG | New Business Development Group | In English | |
| NBDL | Naval Bio-Dynamics Laboratory | In English | → Research institutes → Biological sciences |
| NBEP | Newfoundland Board of Examiners in Psychology | In English | → Organizations and associations → Psychology |
| NBF | Neutral Buoyancy Facility | In English | |
| NBIC | Nanotechnology, Biotechnology, Information Technology and Cognitive Science | In English | → Computer science → Biotechnology → Engineering, technology |
| NBMA | Nonbroadcast Multiple Access Network | In English | → Networks, communication → Telecommunications |
| NBN | Niue Business News | In English | → Newspapers, journalism |
| NBOSS | New-Business Operations Support System | In English | |
| NBR | National Bureau of Asian Research | In English | → Research policy |
| NBS | National Bureau of Standards | In English | → Standardization |
| NBS | Neutral Buoyancy Simulation | In English | |
| NBSAMRF | National Bureau of Standards, Advanced Research Facility | In English | → Research policy → Standardization |
| NBSO | Netherlands Bussiness Support Offices | In English | → Economics |
| NBSSP | National Bureau of Standards Special Publication | In English | → Serial publications, periodicals → Standardization |
| NBSTN | National Bureau of Standards Technical Note | In English | → Serial publications, periodicals → Standardization |
| NBT | Neutral Buoyancy Trainer | In English | |
| NC | National Curriculum | In English | |
| NC | Neuroscience Center | In English | → Mathematics and natural sciences |
| NCA | National Command Authority | In English | |
| NCA | National Communication Association (www.natcom.org) | In English | → Associations → Education |
| NCA | National Credentialing Agency (for Laboratory Personnel) (www.nca-info.org) | In English | → Organizations and associations → Research policy |
| NCA | National Care Association (www.nca.gb.com) | In English | → Associations → Social welfare → Medicine |
| NCA | Northwest College of Art (www.nca.edu) | In English | → Specialized or (poly)technical colleges → Arts |
| NCA | National Campaign for the Arts | In English | → Arts |
| NCAM | Neural Cell Adhesion Molecule | In English | → Biochemistry, biophysics |
| NCAR | National Center for Atmospheric Research (www.ncar.ucar.edu) | In English | → Research institutes → Meteorology, climatology |
| nCaR | Nicotinic Acetylcholine Receptor | In English | → Biochemistry, biophysics |
| NCB | National Certification Body | In English | → Organizations and associations → Standardization |
| NCBA | National Cattlemen's Beef Association (www.beef.org) | In English | → Associations → Agricultural sciences → Food technology |
| NCBI | National Center for Biotechnology Information | In English | → Biotechnology |
| NCC | North American Coordinating Council on Japanese Library Resources | In English | → Libraries |
| NCC | NASA Communications Control | In English | → Spaceflight engineering, astronautics |
| NCC | NASA Class Code | In English | → Spaceflight engineering, astronautics |
| NCC | NTB Control Center | In English | |
| NCC | Network Control Center | In English | → Networks, communication |
| NCC | Navstar Control Center | In English | → Vehicle engineering |
| NCE | Noise Control Engineering Journal | In English | → Serial publications, periodicals → Applied sciences, technology |
| NCECHO | North Carolina Exploring Cultural Heritage Online | In English | → Libraries → Civilization, culture, progress |
| NCEEER | National Council for Eurasian and East European Research | In English | |
| NCG | Nuclear Criteria Group | In English | → Nuclear technology |
| NCG | Nordic Consulting Group | In English | → Consulting |
| NCG | Northern California Grantmakers | In English | → Finance |
| NCHE | National Council for History Education | In English | → Education → History |
| NCI | National Cancer Institute | In English | → Oncology |
| NCIDQ | National Council for Interior Design Certification | In English | → Organizations and associations → Architecture → Drawing and applied arts |
| NCIMB | National Collections of Industrial, Marine and Food Bacteria (www.ncimb.com) | In English | → Biological sciences → Food technology |
| NCIP-IG | NISO Circulation Interchange Protocol Implementers Group | In English | → Organizations and associations → Libraries |
| NCIU | Network Common Interface Unit | In English | → Human-computer interaction → Networks, communication |
| NCJLT | National Council of Japanese Language Teachers (www.ncjlt.org) | In English | → Organizations and associations → Education → Language, linguistics, literature |
| NCLRC | National Capital Language Resource Center (www.nclrc.org) | In English | → Serial publications, periodicals → Education → Language, linguistics, literature |
| NCM | National Cryptologic Museum (www.nsa.gov/museum/) | In English | → Museums → Computer science → Mathematics |
| NCM | New California Media | In English | → Organizations and associations → Newspapers, journalism |
| NCM | National Cartoon Museum (www.cartoon.org) | In English | → Museums → Graphic industries, printing, publishing → Cinema, movies |
| NCM | National Capital Marathon | In English | → Sport, physical exercises |
| NCM | Neural Control of Movement Society (http://ncm-society.org) | In English | → Organizations and associations → Neurology |
| NCM | National Corvette Museum (www.corvettemuseum.com) | In English | → Museums → Automobile manufacturing |
| NCM | Network Connection Manager | In English | → Software → Networks, communication |
| NCMC | NORAD Cheyenne Mountain Complex | In English | |
| NCNS | Network: Computation in Neural Systems | In English | → Serial publications, periodicals → Artificial intelligence |
| NCO | Numerically Controlled Oscillator | In English | → Electronics |
| NCOLR | National Council on Orientalist Library Resources | In English | → Libraries → Organizations and associations → Linguistics |
| NCOS | National Commission On Space | In English | → Astronomy → Spaceflight engineering, astronautics |
| NCPC | National Cleaner Production Centre | In English | → Environmental technology, water supply, waste management |
| NCPC | National Cleaner Production Center | In English | |
| NCPH | National Council on Public History | In English | → History |
| NCPP | National Center for Children in Poverty | In English | → Social welfare |
| NCRR | National Center for Research Resources (www.ncrr.nih.gov) | In English | → Research institutes → Biological sciences → Medicine |
| NCS | Network Control Station | In English | → Networks, communication |
| NCS | Nutation Control System | In English | |
| NCSA | North Central Sociological Association | In English | → Associations → Sociology |
| NCSA | North Carolina Sociological Association | In English | → Associations → Sociology |
| NCSA | National Center for Supercomputing Applications | In English | → Computer science |
| NCSAS | National Centre for South Asia Studies | In English | → Area studies |
| NCSC | National Computer Security Center | In English | → Computer science |
| NCSSA | National Council of State Sociological Associations | In English | → Associations → Sociology |
| NCSTJ | National Council of Secondary Teachers of Japanese | In English | → Organizations and associations → Education → Language, linguistics, literature |
| NCU | Nozzle Control Unit | In English | |
| ND | NASA Document | In English | → Astronomy → Spaceflight engineering, astronautics |
| NDA | Non-Disclosure Agreement | In English | → Law, jurisprudence |
| NDA | New Drug Application | In English | → Pharmacology, toxicology |
| NDA | National Decommissioning Authority | In English | → Public administration, government → Nuclear technology |
| NDE | Nondestructive Evaluation | In English | → Engineering, technology |
| NDFU | North Dakota Farmers Union | In English | → Organizations and associations → Agricultural sciences |
| NDFU | National Document Fraud Unit | In English | → Police |
| NDGPS | Nationwide Differential Global Positioning System | In English | → Geodesy, cartography → Spaceflight engineering, astronautics → Telecommunications |
| NDI | Nondestructive Inspection | In English | → Engineering, technology |
| NDL | National Diet Library | In English | → Libraries → Nutrition |
| NDLP | New Deal for Lone Parents | In English | → Social welfare |
| NDRO | Nondestructive Readout | In English | → Engineering, technology |
| NDS | Network Distribution Service | In English | → Networks, communication |
| NDS | Nuclear Detection System | In English | → Nuclear technology |
| NDS | Nuclear Data Sheets | In English | → Serial publications, periodicals → Nuclei → Nuclear technology |
| NDST | Nondimensional Special Tool | In English | |
| NDT | Nondestructive Test | In English | → Engineering, technology |
| NDT | Nondestructive Testing | In English | → Engineering, technology |
| NDTE | Nondestructive Testing and Evaluation | In English | → Serial publications, periodicals → 620 |
| NDTF | Nondestructive Test Facility | In English | → Engineering, technology |
| NDTL | Nondestructive Test Laboratory | In English | → Research institutes → Engineering, technology |
| NDU | Navigation Data Unit | In English | → Vehicle engineering |
| NDUS | NUDET Detection User Segment | In English | |
| NDV | NASP Derived Vehicle | In English | → Vehicle engineering |
| NEA | Noise Equivalent Angle | In English | |
| NEA | New Enterprise Associates | In English | |
| NEA | Northeast Asia Program | In English | |
| NEA | Nuclear Energy Agency = AEN | Agencia para la Energía Nuclear | In Spanish |
In English | → Organizations and associations → Nuclear technology |
| NEAAS | New England Conference of the Association for Asian Studies | In English | → Associations → Language, linguistics, literature → Geography, biography, history |
| NEACP | National Emergency Airborne Command Post | In English | → Military engineering → Aeronautics, aircraft |
| NEAF | North East Astronomy Forum | In English | → Astronomy |
| NEAF | National Ethics Application Form | In English | → Ethics |
| NEAF | Near Eastern Archaeology Foundation | In English | → Foundations → Archeology |
| NEAF | National Environmental Advisory Forum | In English | → Organizations and associations → Nature |
| NEALRC | National East Asian Languages Resource Center | In English | → Linguistics |
| NEAS | Near East Archaeological Society | In English | → Organizations and associations → Archeology |
| NEBROC | NEtherlands BRemen OCeanography | In English | → Marine research, oceanography |
| NEC | National Electrical Code | In English | → Electrical engineering |
| NECD | Native Electron Capture Dissociation | In English | |
| NECEF | Near East Cultural and Educational Foundation of Canada | In English | → Foundations → Civilization, culture, progress → Education |
| NeCom | Neural Computation | In English | → Serial publications, periodicals → Computer-based techniques |
| NECTFL | Northeast Conference on the Teaching of Foreign Languages | In English | → 068 → Education → Language, linguistics, literature |
| NED | National Endowment for Democracy | In English | → Democracy |
| NEDINE | NEws DIstribution NEtwork | In English | → Graphic industries, printing, publishing |
| NEDO | New Energy and Industrial Technology Development Organization | In English | → Organizations and associations → Industry, industrial policy → Energy economics |
| NEEDS | NASA End-To-End Data System | In English | → Data → Astronomy → Spaceflight engineering, astronautics |
| NEFCO | Nordic Environment Finance Corporation | In English | |
| NEFD | Noise Equivalent Flux Density | In English | |
| NEHA | New England Historical Association | In English | → Associations → History |
| NEI | Noise Equivalent Irradiance | In English | |
| NEI | Nonexplosive Initiation | In English | → Military engineering |
| NEIC | National Earthquake Information Center (http://earthquake.usgs.gov) | In English | → Organizations and associations → Seismology, earthquakes |
| NEJM | New England Journal of Medicine | In English | → Serial publications, periodicals → Medicine |
| NELA | New England Leather Alliance (www.nelaonline.org) | In English | → Organizations and associations → Leather industry |
| NELC | Near Eastern Languages and Civilizations | In English | → Civilization, culture, progress → Linguistics |
| NELC | Near Eastern Languages and Cultures | In English | → Civilization, culture, progress → Linguistics |
| NELS | Nuclear Effects Link Simulator | In English | → Nuclear technology |
| NEM | Networked and Electronic Media (www.nem-initiative.org) | In English | → Computer science |
| NEMA | National Electric Manufacturers Association (www.nema.org) | In English | → Associations → Electrical engineering |
| NEMA | National Electrical Manufacturers Association | In English | → Associations → Electrical engineering |
| NEMS | NASA Equipment Management System | In English | → Maintenance and logistics → Spaceflight engineering, astronautics |
| NEOBRAIN | Neonatal Estimation Of Brain Damage Risk And Identification of Neuroprotectants | In English | → Neurology → Obstetrics |
| NEON | National Ecological Observatory Network | In English | → Ecology |
| NEP | Nominal Entry Point | In English | |
| NEP | Normal Entry Point | In English | |
| NEP | Noise Equivalent Power | In English | |
| NEPAD | New Partnership for Africa's Development | In English | → Organizations and associations → Development |
| NEPOMUK | Networked Environment for Personalized, Ontology-based Management of Unified Knowledge | In English | → Software → Knowledge management |
| NERSA | National Energy Regulator of South Africa (www.ner.org.za) | In English | → Central administration → Energy economics |
| NERVA | Nuclear Engine for Rocket Vehicle Application | In English | → Nuclear technology → Spaceflight engineering, astronautics |
| NES | Network Encryption System | In English | → Networks, communication → Mathematics |
| NES | Near Eastern Studies | In English | → Area studies |
| NES | Nintendo Entertainment System | In English | |
| NESC | National Electrical Safety Code | In English | → Electrical engineering |
| NESDIS | National Environmental Satellite Data and Information Service | In English | → Nature → Spaceflight engineering, astronautics |
| NESP | Naval Extremely high frequency Satellite Program | In English | → Military engineering → Spaceflight engineering, astronautics |
| NESR | Natural Environment Support Room | In English | |
| NESS | National Environmental Satellite Service | In English | → Environment, environmental sciences → Spaceflight engineering, astronautics |
| NESSI | Networked European Software and Services Initiative (www.nessi-europe.com) | In English | → Organizations and associations → Software |
| NEST | Nuclear Emergency Search Team | In English | → Nuclear technology |
| NET | Nimbus Experiment Team | In English | |
| NET | NASA Employee Team | In English | → Spaceflight engineering, astronautics |
| NET | Noise Equivalent Target | In English | |
| NET | Noise Equivalent Temperature | In English | |
| NET | Neighbourhood Empowerment Team | In English | |
| NET | Norme Européenne de Télécommunication(s) | In English | → Standardization → Telecommunications |
| NETA | New Electricity Trading Arrangements | In English | → Commercial law → Electrical engineering |
| NETCOM | Network Communications | In English | → Telecommunications |
| NETPAC | Network for the Promotion of Asian Cinema | In English | → Organizations and associations → Cinema, movies |
| NETS | New English Translation of the Septuagint | In English | → Judaism → Christianity → Language, linguistics, literature |
| NETSIM | Network Simulation | In English | → Computer simulation |
| NETT | National Emphysema Treatment Trial | In English | → Chest diseases |
| NEVA | New England Vexillological Association | In English | → Associations → 9299 |
| NEVADA | Net Energy Verification And Determination Analyzer | In English | |
| NEVS | NASA Equipment Visibility System | In English | → Spaceflight engineering, astronautics |
| NewAR | New Astronomy Review | In English | → Serial publications, periodicals → Astronomy |
| NEWS | New Engineering Work Schedule | In English | → Engineering, technology |
| NEWS | New Engineering Work System | In English | → Engineering, technology |
| NEXT | Near End CrossTalk | In English | → Telecommunications |