Football, a sport

Facebook, a college social networking website

Fine business, a common ham radio slang term

Fenerbahçe, a Turkish sports club

Framebuffer, in computer technology

Friendship book, a booklet swapped amongst pen pals

Bulgaria Air IATA code

FreeBASIC, a 32-bit compiler using BASIC syntax for DOS, Windows, and Linux

Font Bureau, a type foundry

Fly ball, a type of batted ball or a pitching stat in baseball

Hyundai FB, a series of buses manufactured by Hyundai Motor Company

Firebase, an artillery encampment

Fullback, a position in American football

Fast busy, or Reorder tone, a type of telephone signal