| Acronym | Definition |
|---|
| FOS➣Factory Outlet Store (retail) |
| FOS➣Festival of Speed |
| FOS➣Financial Ombudsman Service (UK) |
| FOS➣Fachoberschule (German school type) |
| FOS➣Fortress of Solitude |
| FOS➣Four of Spades (band) |
| FOS➣Friends of Scouting |
| FOS➣Family of Services (US FEMA) |
| FOS➣Fructo-Oligosaccharides (nutrional supplement) |
| FOS➣Faculty of Science (various universities) |
| FOS➣Focus on Standards |
| FOS➣File Output Stream |
| FOS➣Family of Service |
| FOS➣Failover Services |
| FOS➣Fedora Operating System |
| FOS➣Free Online Scholarship |
| FOS➣Field of Search (sensor management systems) |
| FOS➣Foreign Owned Subsidiaries |
| FOS➣Freedom of the Seas (Royal Caribbean cruise ship) |
| FOS➣Français sur Objectifs Spécifiques (French: French for Specific Purposes) |
| FOS➣Field of Study |
| FOS➣First Order Statistics |
| FOS➣Field Office Supervisor (various organizations) |
| FOS➣First on Stage |
| FOS➣Fundamental Operating System |
| FOS➣Factor Of Safety |
| FOS➣Family of Systems |
| FOS➣From Outer Space |
| FOS➣Figure of Speech |
| FOS➣Faint Object Spectrograph |
| FOS➣Family of Spiders |
| FOS➣free/open source |
| FOS➣Florida Ornithological Society |
| FOS➣Fiber Optic Splicing |
| FOS➣Feat of Strength |
| FOS➣Free Online Scholarship (newsletter) |
| FOS➣French Onion Soup |
| FOS➣Fructooligosacaridos |
| FOS➣Flight Operations Support (various organizations) |
| FOS➣Free Alongside Ship |
| FOS➣Free Overnight Shipping |
| FOS➣Federatie voor Open Scoutisme (Dutch: Federation for Open Scouting; Belgium) |
| FOS➣Fiber Optic Sensor |
| FOS➣Folks on Spokes (bicycle club) |
| FOS➣Federation of Workers Trade Unions (Haiti) |
| FOS➣Friend of the Sea (Sustainable Seafood) |
| FOS➣Florida Orthopaedic Society |
| FOS➣Field Operations Supervisor (Census) |
| FOS➣Foundations of Science (journal; course) |
| FOS➣Family of Schools |
| FOS➣Forward Operating Site (US military) |
| FOS➣First of Season (birding) |
| FOS➣Federal Operations Support (US FEMA) |
| FOS➣Fabric Operating System (Brocade) |
| FOS➣Finnish Optical Society |
| FOS➣Flight Operations System |
| FOS➣Fellowship of the Sun (fictitious religious organization; True Blood; TV show) |
| FOS➣Fabrique d'Outillage de Saint-Étienne (French: Tools Factory of Saint-Étienne; Saint-Étienne, France) |
| FOS➣Finkel-Biskis-Jinkins murine Osteogenicsarcoma (cancer research) |
| FOS➣Fuel Oil Supply |
| FOS➣Front Office System (software) |
| FOS➣Freedom of Services (EU) |
| FOS➣Faint Object Spectrometer |
| FOS➣Free On Steamer |
| FOS➣Finger of Suspicion |
| FOS➣Fish Odor Syndrome |
| FOS➣Flight Operation Segment |
| FOS➣Full of Stool (medical slang) |
| FOS➣Follow On Support |
| FOS➣Full of Stuff (polite form) |
| FOS➣Florida Oceanographic Society |
| FOS➣Full Operational Status |
| FOS➣Fall Of Shot |
| FOS➣Frinton on Sea (Essex, UK) |
| FOS➣First on Scene (first aid) |
| FOS➣Foot of Slope (change of gradient) |
| FOS➣Focus on Solving |
| FOS➣Friends of Science Society (Calgary, AB, Canada) |
| FOS➣Followers of Set (roleplaying) |
| FOS➣Fire Of Savannas |
| FOS➣Freedom of Speech, Inc |
| FOS➣Feature of Size (geometric dimensioning) |
| FOS➣Feet on Street (India) |
| FOS➣Fuel Operator Station |
| FOS➣Found On Shelf |
| FOS➣Follow On Spares |
| FOS➣Follow on Sustainment |
| FOS➣Flight Operations Software |
| FOS➣Failure of Selection (US DoD) |
| FOS➣Fuel Oil Spill |
| FOS➣Frosts of Sweden (knife manufacturer) |
| FOS➣Father Over Shoulder |
| FOS➣Fast Optical Shutter |
| FOS➣Full Operating System |
| FOS➣Feasibility of Support |
| FOS➣Fit or Split |
| FOS➣Forward Observer Software/System |
| FOS➣Fleet Ordnance Support |
| FOS➣Funky Old Soul |
| FOS➣Follow On Ship |
| FOS➣Financial Operations Supervisor |
| FOS➣Friends of Suai |
| FOS➣Front Offside (vehicular collision reports) |
| FOS➣former owner's stamp (used books) |
| FOS➣Fellowship of the Services |
| FOS➣Field Operation Service |
| FOS➣Functional Operational Specification |