| Acronym | Meaning |
| FEMP | Federal Energy Management Program |
| FEMP | Fernald Environmental Management Project |
| FEMP | Free Of Empirical Parameters (e.g. |
| FEN | Free Electron Network |
| FENE | Finitely Extensible Nonlinear Elastic [dumbbell Model] |
| FEOE | Full Equalization Of Orbital Electronegativity |
| FEP | Free Energy Perturbation |
| FEP | Hexafluoropropylene-tetrafluoroethylene Copolymer |
| FEPCA | Federal Environmental Pesticide Control Act |
| FERAM | Ferroelectric Random Access Memory |
| FERC | Federal Energy Regulatory Commission |
| FERMCO | Fernald Environmental Restoration Management Corporation |
| FERP | Field Emission Retarding Potential |
| FERST | Facility For Environmental Remote Sensing And Test |
| FES | Field Emission Spectroscopy |
| FESEM | Field Emission Scanning Electron Microscopy |
| FESTEM | Field-emission Scanning Transmission Electron Microscopy |
| FET | Field Effect Transistor |
| FETAX | Frog Embryo Teratogenesis Assay-Xenopus |
| FETI | Fire, Explosion And Toxicity Index |
| FETI | Fluorescence Energy Transfer Immunoassay |
| FEV | Forced Expiratory Volume (measure Of Lung Function) |
| FEV1 | Forced Expiratory Volume In The First Second (lung Function) |
| FEWS | Fiber-optic Evanescent Wave Spectroscopy |
| FF-MBPT | Finite-field Many-body Perturbation Theory |
| FFA | Flammable Fabrics Act |
| FFA | Free Fatty Acid |
| FFAR | Fuel And Fuel Additive Registration |
| FFCA | Federal Facility Compliance Act |
| FFDCA | Federal Food, Drug, And Cosmetic Act (US) |
| FFE | Free Flow Electrophoresis |
| FFEM | Freeze-fracture Electron Microscopy |
| FFF | Field-flow Fractionation |
| FFFSG | Fossil Fuel Fired Steam Generator |
| FFIS | Federal Facilities Information System |
| FFITP | Free-flow Isotachophoresis |
| FFM | Finite Field Method (in Mol. Polarizabilities Calcns.) |
| FFM | Friction Force Microscopy |
| FFP | Femtosecond Flash Photolysis |
| FFP | Fresh Frozen Plasma |
| FFPC | Forced-flow Planar Chromatog. |
| FFPE | Formalin-fixed Paraffin-embedded |
| FFS | Flame Fluorescence Spectroscopy |
| FFSHC | Field Federal Safety And Health Councils |
| FFT | Fast Fourier Transform |
| FFTB | Final Focus Test Beam |
| FFTF | Fast Flux Test Facility |
| FFV | Flexible Fuel Vehicle |
| FFZE | Free-flow Zone Electrophoresis |
| FGAN | Fertilizer Grade Ammonium Nitrate |