| Acronym | Meaning |
 | EFI | Enrico Fermi Institute |
 | EFNS | Educational Foundation For Nuclear Science |
 | EFT | Enhanced Forecaster Tools |
 | EFTA | European Free Trade Association |
 | EFTC | European Fluorocarbon Technical Committee |
 | EG&G | Inc. |
 | EGA | Enhanced Graphics Adapter |
 | EGD | Effluent Guidelines Division |
 | EGP | Exterior Gateway Protocol |
 | EGS | European Geophysical Society |
 | EGSE | Electronic Ground Support Equipment |
 | EGTF | Electron Gun Test Facility |
 | EH | Oxidation Potential |
 | EH | Assistant Secretary For Environment |
 | EHF | Extremely High Frequency |
 | EHF | Extremely High Frequency |
 | EI | Electron Ionization |
 | EIA | Energy Information Administration |
 | EIA | Electronic Industries Association |
 | EIB | Environmental Improvement Board |
 | EIC | Earth Information System |
 | EICC | Emergency Information Control Center |
 | EINET | Enterprise Integration Network |
 | EIR | Eidgenossisches Institut Fur Reaktorforschung |
 | EIS | Environmental Impact Statement |
 | EISA | Extended Industry Standard Architecture |
 | EISCAT | European Incoherent Scatter Radar System |
 | EISPACK | Eigensystem Package Subroutine Computing Facility |
 | EL NI-O | The Little Boy |
 | ELCHEM | Electrified Clouds As Sources Of NOx |
 | ELDO | European Launcher Development Organization |
 | ELDOME | Electra Radome |
 | ELDORA | Electra Doppler Radar |
 | ELDORA/ASTERIX | France-United States Collaborative Development Of The ELDORA |
 | ELF | Extremely Low Frequency |
 | ELF | Extremely Low Frequency |
 | ELGA | (French) Study Of African Squall Lines |
 | ELI | Environmental Law Institute |
 | ELINT | Electronic Intelligence |
 | ELLWAS | Enhanced Low-Level Windshear Alert System |
 | ELP | Emission Line Polarimeter |
 | ELP | Equipment Loan Program |
 | ELSCAM | Electra Scalar Measurements |
 | ELVD | Every Launch Vehicle Directorate |
 | ELVIS | ELectromagnetic Very Weak Instabilities Saturated |
 | ELVIS | Export Licensing Voice Information System |
 | EM | Engineering Model |
 | EM | Electromagnetic |
 | EM | Electromagnetic Conductivity |
 | EM | Electronic Mail |