| LCD | Liquid Crystal Display | In English | → Human-computer interaction → Electronics |
| LCIE | Laboratoire Central des Industries Électriques | In English | → Research institutes → Electrical engineering |
| LCM | Linz Center of Mechatronics | In English | → Electrical engineering |
| LDMS | Laboratoire de Dynamique des Machines et des Structures | In French | → Research institutes |
| LE | London Electricity | In English | → Electrical engineering |
| LEAT | Laboratoire d'Électronique, Antennes et Télécommunications | In French | → Research institutes → Electronics → Telecommunications |
| LEC | Lockheed Electronics Company | In English | → Electronics |
| LECAP | Laboratoire d'Étude et de Commande Automatique de Processus | In French | → Research institutes → Electronics |
| LED | Light-Emitting Diode | In English | → Electronics |
| LEG | London Electricity Group | In English | → Electrical engineering |
| LETI | Laboratoire d'Électronique et de Technologie de l'Informatique | In French | → Research institutes → Computer science → Electronics |
| LGE | Laboratoire de Génie Électrique | In French | → Research institutes → Electrical engineering |
| LIMSI | Laboratoire d'Informatique pour la Mécanique et les Sciences de l'Ingénieur | In French | → Research institutes → Computer science |
| LIRMM | Laboratoire d’Informatique, de Robotique et de Micro-électronique de Montpellier | In French | → Research institutes → Computer science → Electronics |
| LISMMA | Laboratoire d'Ingénierie des Systèmes Mécaniques et MAtériaux | In French | → Research institutes |
| LMIF | Lower Mechanical Integration Frame | In English | |
| LMO | Lilloise Machines Uutils | In French | → Trade |
| LO | Lubricating Oil | In English | |
| LOI | Light Overseas Investments Limited | In English | → Electrical engineering → Environmental technology, water supply, waste management |
| LPA | Low-Power Amplifier | In English | → Electrical engineering |
| LPTTL | Low-Pressure Transistor-Transistor Logic | In English | → Electronics |
| LSIC | Large-Scale Integrated Circuit | In English | → Electronics |
| LTT | Laboratory of Thermal Turbomachines | In English | → Research institutes |
| LV | Low-Voltage | In English | → Electrical engineering |
| LVD | Low Voltage Directive | In English | → Electrical engineering |
| LVDT | Linear Voltage Differential Transformer | In English | → Electrical engineering |
| LVE | Low-Voltage Electronics | In English | → Electronics |
| LVE-CCC | Low Voltage Electrical Equipment Certification Coordination Committee | In English | → Electrical engineering |
| LVP | Low-Voltage Pressure | In English | → Electrical engineering |
| LVPS | Low-Voltage Power Supply | In English | → Electrical engineering |
| LVR | Low-Voltage Release | In English | → Electrical engineering |
| LWBR | Light Water Breeder Reactor | In English | → Nuclear technology |
| LWCHWR | Light Water Cooled Heavy Water Reactor | In English | → Nuclear technology |
| LWGR | Light Water Cooled Graphite Reactor | In English | → Nuclear technology |
| MAAE | Mezinárodní agentura pro atomovou energii (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 = 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 = UAEA | Uluslararası Atom Enerji Ajansı | In Turkish = IAEA | สำนักงานพลังงานปรมาณูระหว่างประเทศ | In Thai = EANA | Energia Atomikoaren Nazioarteko Agentzia | In Basque |
In Czech | → International relations → Energy economics → Nuclear technology |
| MAAE | Меѓународна агенција за атомска енергија (www.iaea.org) = IAAE, IAEA, AIEA, МААЕ, IAEO, OIEA, סבא"א, МАГАТЭ, MAEA, МАГАТЕ, UAEA, EANA (look above) |
In Macedonian | → International relations → Energy economics → Nuclear technology |
| MAB | Mechanical Automation Breadboard | In English | |
| MACE | Mechanical Antenna Control Electronics | In English | → Electronics |
| MaDes | Machine Design | In English | → Serial publications, periodicals |
| MAEA | Międzynarodowa Agencja Energii Atomowej (www.iaea.org) = MAAE, IAAE, IAEA, AIEA, МААЕ, IAEO, OIEA, סבא"א, МАГАТЭ, МАГАТЕ, UAEA, EANA (look above) |
In Polish | → International relations → Energy economics → Nuclear technology |
| MAI | Mécanique et Automatismes Industriels | In French | |
| Mockup And Integration Laboratory | In English | → Research institutes | |
| MARC | Multiple Artificial Retina Chipset | In English | → Medicine → Electronics |
| MARN | Mission d'Appui à la gestion du Risque Nucléaire | In French | → Nuclear technology |
| MCAE | Mechanical Computer Aided Engineering | In English | → Computer-based techniques |
| MCM | Multi Chip Module | In English | → Electronics |
| MCR | Molded Carrier Ring | In English | → Electronics |
| MDE | Modular Display Electronics | In English | → Electronics |
| MDE | Maîtrise de la Demande en Électricité | In French | → Energy economics → Electrical engineering |
| MDF | Manipulator Development Facility | In English | → Electrical engineering |
| MEA | Main Electronics Assembly | In English | → Electronics |
| MEB | Main Electronics Box | In English | → Electronics |
| MECA | Missile Electronics Computer Assembly | In English | → Computer science → Electronics → Military engineering |
| MECCA | Master Electrical Common Connector Assembly | In English | → Electrical engineering |
| MecEn | Mechanical Engineering | In English | → Serial publications, periodicals |
| MECO | Mekong Energy Company Limited | In English | → Energy economics → Electrical engineering |
| MEDS | Mechanical Engineering Design System | In English | |
| MEEI | Magyar Elektrotechnikai Ellenőrző Intézetre | In Hungarian | → Electrical engineering |
| MEEI | Mechanical Engineering Energy Institute | In English | → Energy economics |
| MEK | Magyar Elektronikus Könyvtár | In Hungarian | → Electronics |
| MELC | Mechanical Engineering Liaison Committee | In English | → Organizations and associations |
| MELF | Metal ELectrical Face | In English | → Electrical engineering |
| MEM | Mid-Deck Electronics Module | In English | → Electronics |
| MEMS | Micro-Electro-Mechanical System = MEMS | Mikro Elektro-Mekanik Sistem | In Turkish |
In English | → Electrical engineering |
| MEMS | Mikro Elektro-Mekanik Sistem = (look above) |
In Turkish | → Electrical engineering |
| MeReC | Mechanics Research Communications | In English | → Serial publications, periodicals |
| MERL | Mitsubishi Electric Research Labs (www.merl.com) | In English | → Electrical engineering |
| MFSP | Macrofunction Signal Processor | In English | → Electronics → Telecommunications |
| MGSE | Mechanical Ground Support Equipment | In English | |
| MHI | Mitsubishi Heavy Industries | In English | → Spaceflight engineering, astronautics |
| MIC | Monolithic Integrated Circuit | In English | → Electronics |
| MiElC | Military Electronics Countermeasures | In English | → Serial publications, periodicals → Military engineering → Electronics |
| MiEng | Microelectronic Engineering | In English | → Serial publications, periodicals → Electronics |
| MIF | Mechanical Integration Frame | In English | |
| MiI | Microelectronics International | In English | → Serial publications, periodicals → Electronics |
| MIRE | Mesure et système d’Information des Réseaux Électriques | In French | → Electrical engineering |
| MiRe | Microelectronics Reliability | In English | → Serial publications, periodicals → Electronics |
| MJ | Mechanical Joint | In English | |
| MLI | Modulation de Largeur d'Impulsion | In French | → Electrical engineering |
| MMA | Moving Mechanical Assembly | In English | |
| MMAS | Mechanized Material Accountability System | In English | → Maintenance and logistics |
| MMC | Master Microprocessor Control | In English | → Hardware → Electronics |
| MMIA | Monolithic Microwave Integrated Amplifier | In English | → Electronics |
| MMIC | Millimeter-Wave Monolithic Integrated Circuit | In English | → Electronics |
| MMIC | Monolithic Microwave Integrated Circuit | In English | → Electronics |
| MNOS | Metal Nitride Oxide Semiconductor | In English | → Electronics |
| MOCN | Machine-Outil à Commande Numérique | In French | → Computer-based techniques |
| MOPA | Master Oscillator Power Amplifier | In English | → Electrical engineering |
| MOS | Metal Oxide Semiconductor | In English | → Electronics |
| MOSFET | Metal-On-Silicon Field-Effect Transistor | In English | → Electronics |
| MotZe | Motortechnische Zeitschrift | In German | → Serial publications, periodicals → Vehicle engineering |
| MOX | Mixed OXyde fuel | In English | → Nuclear technology |
| MPBS | Main Power Bus Supply | In English | → Electrical engineering |
| MPD | Main Dc Power Distributor | In English | → Electrical engineering |
| MPFD | Microdevices: Physics and Fabrication Technologies | In English | → Serial publications, periodicals |
| MPL | Minimum Power Level | In English | → Electrical engineering |
| MPL | Mechanical Parts List | In English | → Maintenance and logistics |
| MPM | Manipulator Positioning Mechanism | In English | |
| MPMP | Mechanical Parts, Material & Process(es) | In English | → Maintenance and logistics |
| MPOR | Master Power-On Reset | In English | → Electrical engineering |
| MRA | Mechanical Readiness Assessment | In English | |
| MRMS | Mobile Remote Manipulator System | In English | |
| MS | Machine Screw | In English | |
| MS | Mechanical System | In English | |
| MSE | Mechanical Support Equipment | In English | |
| MSG | Mechanical Subsystem Group | In English | |
| MSL | Mechanical Systems Laboratory | In English | → Research institutes |
| MSM | Mechanics of Structures and Machines | In English | → Serial publications, periodicals |
| MSMA | Maintenance des Systèmes Mécaniques Automatisés | In French | → Maintenance and logistics |
| MSS | Mechanical Support System | In English | |
| MSSP | Mechanical Systems and Signal Processing | In English | → Serial publications, periodicals → Electronics |
| MST | Mikrosystemtechnik | In German | → Electronics |
| MTDM | Mechanics of Time-Dependent Materials | In English | → Serial publications, periodicals |
| MTEE | Maintenance Test Equipment, Electrical | In English | → Maintenance and logistics → Electrical engineering |
| MTEM | Maintenance Test Equipment, Mechanical | In English | → Maintenance and logistics |
| MTK | Mechanical Timekeeping | In English | |
| MTK | Mechanized Timekeeping | In English | |
| MTM | Mechanical Test Model | In English | |
| MWV | Maximum Working Voltage | In English | → Electrical engineering |
| NacEl | Nachrichten Elektronik | In German | → Serial publications, periodicals → Electronics |
| NAM | Nuclear Assessment Methodology | In English | → Nuclear technology |
| NCG | Nuclear Criteria Group | In English | → Nuclear technology |
| NCO | Numerically Controlled Oscillator | In English | → Electronics |
| NDA | National Decommissioning Authority | In English | → Public administration, government → Nuclear technology |
| NDS | Nuclear Detection System | In English | → Nuclear technology |
| NDS | Nuclear Data Sheets | In English | → Serial publications, periodicals → Nuclei → Nuclear technology |
| NEA | Nuclear Energy Agency = AEN | Agencia para la Energía Nuclear | In Spanish |
In English | → Organizations and associations → Nuclear technology |
| NEC | National Electrical Code | In English | → Electrical engineering |
| NEC | Nederlands Elektrotechnisch Comité | In Dutch | → Organizations and associations → Electrical engineering |
| NEK | Norsk Elektroteknisk Komite | In Norwegian | → Organizations and associations → Electrical engineering |
| NELS | Nuclear Effects Link Simulator | In English | → Nuclear technology |
| NEMA | National Electrical Manufacturers Association | In English | → Associations → Electrical engineering |
| NEMA | National Electric Manufacturers Association (www.nema.org) | In English | → Associations → Electrical engineering |
| NERSA | (Société centrale) Nucléaire Européenne à neutrons Rapides SA | In French | → Nuclear technology → Electrical engineering |
| NERVA | Nuclear Engine for Rocket Vehicle Application | In English | → Nuclear technology → Spaceflight engineering, astronautics |
| NESC | National Electrical Safety Code | In English | → Electrical engineering |
| NEST | Nuclear Emergency Search Team | In English | → Nuclear technology |
| NETA | New Electricity Trading Arrangements | In English | → Commercial law → Electrical engineering |
| NH&S | Nuclear Hardening and Survivability | In English | → Nuclear technology |
| NIFS | National Institute for Fusion Science | In English | → Research institutes → Nuclear, atomic, and molecular physics → Nuclear technology |
| NIFTE | Non-Inertive Feedback Thermofluidic Engine | In English | |
| NIM | Nuclear Instrumentation Module | In English | → Nuclear technology |
| NIMP | Nuclear Instruments and Methods in Physics Research | In English | → Serial publications, periodicals → Nuclei → Nuclear technology |
| NMOS | Negative-Type Metal Oxide Semiconductor | In English | → Electronics |
| NMTBA | National Machine Tool BUilders' Association | In English | → Associations |
| NNPT | Nuclear Non-Proliferation Treaty | In English | → International relations → Nuclear technology → Military engineering |
| NNSA | National Nuclear Security Administration | In English | → Central administration → Nuclear technology |
| NOMIS | Nuclear Operations and Maintenance Information Service | In English | → Maintenance and logistics → Nuclear technology |
| NPL | Normal Power Level | In English | → Electrical engineering |
| NPS | Nuclear Power Station | In English | → Nuclear technology |
| NRB | Nuclear Reactor/Brayton | In English | → Nuclear technology |
| NRC | Nuclear Regulatory Commission | In English | → Nuclear technology |
| NRDS | Nuclear Rocket Development Station | In English | → Nuclear technology → Spaceflight engineering, astronautics |
| NS | Nuclear Shuttle | In English | → Nuclear technology → Spaceflight engineering, astronautics |
| NSCCA | Nuclear Safety Cross-Check Analysis | In English | → Nuclear technology |
| NSE | Nuclear Science Engineering | In English | → Serial publications, periodicals → Nuclei → Nuclear technology |
| NTPC | Nam Theun 2 Power Company (www.namtheun2.com) | In English | → Electrical engineering |
| NTSC | Nuclear Technology Safety Center | In English | → Nuclear technology |
| NucFS | Nuclear Fusion Special Supplement | In English | → Serial publications, periodicals → Nuclei → Nuclear technology |
| NucFu | Nuclear Fusion | In English | → Serial publications, periodicals → Nuclei → Nuclear technology |
| NucIM | Nuclear Instruments and Methods | In English | → Serial publications, periodicals → Nuclei → Nuclear technology |
| NucTe | Nuclear Technology | In English | → Serial publications, periodicals → Nuclei → Nuclear technology |
| NucTF | Nuclear Technology Fusion | In English | → Serial publications, periodicals → Nuclei → Nuclear technology |
| NUDET | Nuclear Detonation | In English | → Nuclear technology → Military engineering |
| NuEnD | Nuclear Engineering and Design | In English | → Serial publications, periodicals → Nuclei → Nuclear technology |
| NUSS | NUclear Safety Standards | In English | → Nuclear technology |
| NV | Nuclear Vehicle | In English | → Nuclear technology → Vehicle engineering |
| NWE | Nuclear Weapons Effect | In English | → Nuclear technology → Military engineering |
| NWMP | Nuclear Weapons Monitor Plan | In English | → Nuclear technology → Military engineering |
| OAME | Orbital Attitude and Maneuvering Electronics | In English | → Electronics → Spaceflight engineering, astronautics |
| OARME | Oxygen Atom Reaction Materials Experiment | In English | → Nuclear, atomic, and molecular physics → Nuclear technology |
| OAS | Office Automation System | In English | |
| OCA | Ouest Convoyeur et Automatisme | In French | |
| OEW | Oberschwäbische Elektrizitätswerke | In German | → Electrical engineering |
| OGK | Optovaya Giéniérirouyouchtchaya Kompaniya = ОГК | Оптовая генерирующая компания | In Russian |
In Russian | → Energy economics → Electrical engineering |
| OIEA | Organismo Internacional de Energía Atómica (www.iaea.org) = MAAE, IAAE, IAEA, AIEA, МААЕ, IAEO, סבא"א, МАГАТЭ, MAEA, МАГАТЕ, UAEA, EANA (look above) |
In Spanish | → International relations → Energy economics → Nuclear technology |
| OMEC | Organic Materials for Electronics Consortium | In English | → Chemistry → Electronics |
| ONE | Office National d’Électricité | In French | → Central administration → Electrical engineering |
| OPEN | Organisation de Producteurs d'Énergie Nucléaire | In French | → Organizations and associations → Nuclear technology |
| OPRI | Office de Protection contre les Rayonnements Ionisants | In French | → Nuclear technology |
| ORE | Opérateur de Réseau Électricité | In French | → Electrical engineering |
| ORM | Operational Reactivity Margin | In English | → 53912 → Nuclear technology |
| OSGE | Observatoire Statistique du Groupe EDF | In French | → Electrical engineering |
| ÖVK | Österreichischer Verein für Kraftfahrzeugtechnik (www.?vk.at) | In German | → Organizations and associations |
| P3S | Power Systems Supports and Services | In English | → Electrical engineering |
| PAC | Pile à combustible | In French | → Energy economics → Electrical engineering |
| PACE | Power and Control Electronics | In English | → Electronics |
| PAPEETE | Pour Améliorer les Performances Énergétiques ET Environnementales | In French | → Energy economics → Electrical engineering |
| PASTISS | Professional Analysis Software Tool for Inflatable Space Structures | In English | → Software |
| PBD | Payload Bay Door | In English | |
| PBDM | Payload Bay Door Mechanism | In English | |
| PC | Printed Circuit | In English | → Electronics |
| PCA | Power Controller Assembly | In English | → Electrical engineering |
| PCA | Power Conditioning Assembly | In English | → Electrical engineering |
| PCB | Power Circuit Breaker | In English | → Electrical engineering |
| PCB | Printed Circuit Board | In English | → Electronics |
| PCB | Power Control Box | In English | → Electrical engineering |
| PCE | Power Conditioning Electronics | In English | → Electrical engineering → Electronics |
| PCE | Power Conditioning Equipment | In English | → Electrical engineering |
| PCI-E | Peripheral Component Interconnect Express | In English | → Computer science → Electronics |