| Acronym | Meaning |
| FAT | Fatty Acid Translocase |
| FATE | Functional Attributes In Terrestrial Ecosystems |
| FATES | FIRFA And TSCA Enforcement System (now Known As SSTS) |
| FATT | Fracture-appearance Transition Temperature |
| FBA | First Born Approximation |
| FBA | Fluidized Bed Afterburner |
| FBA | Fluorescent Brightening Agent |
| FBBR | Fluidized Bed Biofilm Reactor |
| FBC | Fluidized Bed Combustor |
| FBCB | Fixed Bed Circulating Bioreactor (for Wastewater Treatment) |
| FBE | Flat Bed Electrophoresis |
| FBEM | Fixed Beam Electron Microscopy |
| FBF | Forearm Blood Flow |
| FBG | Fasting Blood Glucose |
| FBG | Fiber Bragg Grating |
| FBL | Fixed Bed Loop |
| FBR | Fast Breeder Reactor |
| FBR | Finite Basis Representation (in Wave Fct. Calcn. For Nuclear Motion On Potential Energy Surface) |
| FBR | Fixed Bed Reactor |
| FBS | Fetal Bovine Serum |
| FBTR | Fast Breeder Test Reactor |
| FC | Frozen Core (approxn. For Electron-atom Scattering Calcns.) |
| FCA | Frozen-core Appproximation |
| FCA | Fuzzy Cluster Analysis |
| FCAW | Flux-cored Arc Welding |
| FCC | Flight Control Computer |
| FCC | Food Chemicals Codex |
| FCC | Face Centered Cubic |
| FCC | Flat Collect Circuit (in Solar Cell Array For Spacecraft) |
| FCC | Fluidized Catalytic Cracking |
| FCCC | Framework Convention On Climate Change |
| FCCP | Trifluoromethoxy Carbonylcyanide Phenylhydrazone |
| FCCSET | Federal Coordinating Council On Science |
| FCCU | Fluidized Catalytic Cracking Unit |
| FCD | Fault Consequence Digraph |
| FCF | Franck-Condon Factor |
| FCG | Fatigue Crack Growth |
| FCHF | Frozen-core Hartree-Fock |
| FCHL | Familial Combined Hyperlipidemia |
| FCI | Fuel Coolant Interaction |
| FCI | Full Configuration Interaction |
| FCM | Finite-cluster Model (for Calcns. On Electromigration) |
| FCP | Function Counterpoise (method For Eliminating Basis Set Superposition Error) |
| FCPC | Full-core Plus Correlation (calcn. Method) |
| FCS | Fetal Calf Serum |
| FCS | Fluorescence Correlation Spectroscopy |
| FCSA | Frequency-corrected Sudden Approxn. (in Mol. Collision Calcns.) |
| FCV | Fast Cyclic Voltammetry |
| FCV | Feline Calicivirus |
| FCVA | Filtered Cathodic Vacuum Arc |