| FOS | freedom of speech | 言论自由 |
| FOS | FULL OF SIZE | 齐码 |
| FOS | free on steamer | 蒸汽船上交货（价） |
| FOS | Fiber Optic Sensor | 光纤传感器 |
| FOS | Friends of Science Society (Calgary, AB, Canada) | 科学之友协会（卡尔加里，AB，加拿大） |
| FOS | Fleet Ordnance Support | 舰队军械支援 |
| FOS | Fast Optical Shutter | 快速光学快门 |
| FOS | Freedom of the Seas (Royal Caribbean cruise ship) | 海洋自由号（皇家加勒比游轮） |
| FOS | Factory Outlet Store (retail) | 工厂直销店（零售） |
| FOS | Florida Ornithological Society | 佛罗里达鸟类学会 |
| FOS | Father Over Shoulder | 肩上的父亲 |
| FOS | Financial Ombudsman Service (UK) | 金融监察员服务（英国） |
| FOS | Found On Shelf | 在机框上找到 |
| FOS | Free Online Scholarship (newsletter) | 免费在线奖学金（简讯） |
| FOS | Finkel-Biskis-Jinkins murine Osteogenicsarcoma (cancer research) | Finkel Biskis-Jinkins小鼠成骨肉瘤（癌症研究） |
| FOS | Faint Object Spectrometer | 微弱物体光谱仪 |
| FOS | Full Operational Status | 完全运行状态 |
| FOS | Feasibility of Support | 支持的可行性 |
| FOS | Fuel Oil Spill | 燃油泄漏 |
| FOS | Faint Object Spectrograph | 微弱物体光谱仪 |
| FOS | Finger of Suspicion | 怀疑之指 |
| FOS | Forward Operating Site (US military) | 前方作战基地（美军） |
| FOS | Florida Oceanographic Society | 佛罗里达海洋学会 |
| FOS | Forward Observer Software/System | 前沿观察员的软件系统 |
| FOS | Financial Operations Supervisor | 财务运营主管 |
| FOS | Forensic and Osteoarchaeological Services | 法医和骨考古服务 |
| FOS | Forrest, Western Australia, Australia | 福雷斯特，西澳大利亚州，澳大利亚 |
| FOS | Fantastically Oaky Stuff | 神奇的Oaky Stuff |
| FOS | Freak Out Squad | 怪胎小队 |
| FOS | Forward Observer System | 前向观察系统 |
| FOS | Full of stool (constipated) | 大便满（便秘） |
| FOS | FederaciÓn Obrera Socialista | FederaciÓn Obrera Socialista |
| FOS | Furniture Online Shop | 家具网上商店 |
| FOS | Fructo-OligoSaccharide | 低聚果糖 |
| FOS | Full Of Shit | 全是狗屎 |
| FOS | Field of Study | 研究领域 |
| FOS | Factor Of Safety | 安全系数 |
| FOS | Fuel Oil Supply | 燃油供应 |
| FOS | Freedom of Speech, Inc | 言论自由公司 |
| FOS | Fructooligosacaridos | 低聚果糖 |
| FOS | former owner's stamp (used books) | 前任拥有者的邮票(二手书) |
| FOS | Fit or Split | 拟合或拆分 |
| FOS | First of Season (birding) | 第一季（观鸟） |
| FOS | Full Operating System | 完整操作系统 |
| FOS | Funky Old Soul | 有趣的老灵魂 |
| FOS | Follow On Support | 后续支持 |
| FOS | Federation of Workers Trade Unions (Haiti) | 工人工会联合会（海地） |
| FOS | Fall Of Shot | 铅球坠落 |
| FOS | Frinton on Sea (Essex, UK) | 海上弗里顿（英国埃塞克斯） |
| FOS | Fabric Operating System (Brocade) | 结构操作系统（Brocade） |
| FOS | Foot of Slope (change of gradient) | 坡脚（坡度变化） |
| FOS | Follow On Spares | 后续备件 |
| FOS | Full of Stuff (polite form) | 满满的东西（礼貌的形式） |
| FOS | Field Operations Supervisor (Census) | 现场作业主管（人口普查） |
| FOS | Follow On Ship | 后续装运 |
| FOS | Family of Systems | 系统系列 |
| FOS | Full of Stool (medical slang) | 充满大便（医学俚语） |
| FOS | Followers of Set (roleplaying) | 布景跟随者（角色扮演） |
| FOS | Friends of Suai | 苏艾之友 |
| FOS | Fire Of Savannas | 草原之火 |
| FOS | Follow on Sustainment | 后续维持 |
| FOS | Fuel Operator Station | 燃油操作员站 |
| FOS | fiberoptic sigmoidoscopy | 纤维乙状结肠镜检查 |
| FOS | From Outer Space | 来自外层空间 |
| FOS | fissura orbitalis superior | 眶上裂 |
| FOS | Feature of Size (geometric dimensioning) | 尺寸特征（几何尺寸） |
| FOS | Fructo-Oligosaccharides (nutrional supplement) | 果糖寡糖（营养补充剂） |
| FOS | fractional osteoid surface | 部分类骨表面 |
| FOS | Functional Operational Specification | 功能操作规范 |
| FOS | Front Offside (vehicular collision reports) | 前方偏离（车辆碰撞报告） |
| FOS | Flight Operation Segment | 飞行操作段 |
| FOS | Focus on Solving | 专注于解决 |
| FOS | Failure of Selection (US DoD) | 选择失败（美国国防部） |
| FOS | Free Online Scholarship | 免费在线奖学金 |
| FOS | Flight Operations Software | 飞行操作软件 |
| FOS | Flight Operations System | 飞行操作系统 |
| FOS | Fellowship of the Services | 服务奖学金 |
| FOS | Friend of the Sea (Sustainable Seafood) | 海洋之友（可持续海鲜） |
| FOS | French Onion Soup | 法式洋葱汤 |
| FOS | Festival of Speed | 速度节 |
| FOS | Fundamental Operating System | 基本操作系统 |
| FOS | free/open source | 自由/开源软件 |
| FOS | Figure of Speech | 修辞手法 |
| FOS | Freedom of Services (EU) | 服务自由（欧盟） |
| FOS | Field of Search (sensor management systems) | 搜索领域（传感器管理系统） |
| FOS | Florida Orthopaedic Society | 佛罗里达骨科学会 |
| FOS | Foundations of Science (journal; course) | 科学基础（期刊；课程） |
| FOS | Front Office System (software) | 前台系统（软件） |
| FOS | Friends of Scouting | 童军之友 |