Replies

I had to look that one up:

Acronym Definition
FOS Financial Ombudsman Service (UK)
FOS Fructo-Oligosaccharides (nutrional supplement)
FoS Festival of Speed
FOS Friends of Scouting
FOS Free Online Scholarship (newsletter)
FOS Fundamental Operating System
FOS Faint Object Spectrograph
FOS free/open source
FoS Field of Study
FOS Family of Systems
FOS Florida Ornithological Society
FOS Fructooligosacaridos
FOS Factor Of Safety
FOS From Outer Space
FOS Fiber Optic Sensor
FOS Foundations of Science (journal; course)
FOS Figure of Speech
FOS Federation of Workers Trade Unions (Haiti)
FOS Freedom of the Seas (Royal Caribbean cruise ship)
FOS Free Alongside Ship
FOS First of Season (birding)
FOS French Onion Soup
FOS Forward Operating Site (US military)
FOS Faint Object Spectrometer
FOS Free On Steamer
FOS Freedom of Services (EU)
FOS Flight Operations System
FOS Friend of the Sea (Sustainable Seafood)
FOS Flight Operation Segment
FOS Full Operational Status
FOS Florida Orthopaedic Society
FOS Fabric Operating System (Brocade)
FOS Factory Outlet Store (retail)
FOS Full of Stool (medical slang)
FOS Florida Oceanographic Society
FOS Finger of Suspicion
FOS Front Office System (software)
FOS Full of Stuff (polite form)
FoS Friends of Science Society (Calgary, AB, Canada)
FOS Failure of Selection (US DoD)
FOS Fuel Oil Supply
FOS Field Operations Supervisor (Census)
FoS Followers of Set (roleplaying)
FOS Flight Operations Software
FOS Fire Of Savannas
FOS Frinton on Sea (Essex, UK)
FOS Freedom of Speech, Inc
FOS Feature of Size (geometric dimensioning)
FOS Follow On Support
FOS Field of Search (sensor management systems)
FOS Fuel Operator Station
FOS Found On Shelf
FOS Follow On Spares
FOS Follow on Sustainment
FOS Foot of Slope (change of gradient)
FOS Fall Of Shot
FoS Focus on Solving
FOS Full Operating System
FOS Fuel Oil Spill
FOS Father Over Shoulder
FOS Front Offside (vehicular collision reports)
FOS Fast Optical Shutter
FOS Feasibility of Support
FOS Fit or Split
FOS Funky Old Soul
FOS Forward Observer Software/System
FOS Fleet Ordnance Support
FOS Financial Operations Supervisor
FOS Follow On Ship
FOS Fellowship of the Services
FOS former owner’s stamp (used books)
FOS Friends of Suai
FOS Functional Operational Specification
FOS Finkel-Biskis-Jinkins murine Osteogenicsarcoma (cancer research)

Which did you mean?

LOL