semaphore

/ˌsɛməˈfɔər/

Other forms: semaphores; semaphoring; semaphored

A semaphore is a gadget used for conveying signals. Semaphores have either lights or mechanical arms that move.

The word semaphore is related to a Greek word meaning "signal," and that's exactly the purpose of semaphores: they give signals. The place you're most likely to have seen a semaphore is a railroad crossing: the gadget with moving arms is a semaphore. Some semaphores have mechanical arms, while others just use lights to communicate. A semaphore system can also use flags. In all cases, semaphores give visual signals that communicate something important, especially to people traveling.

Definitions of semaphore

1. noun

   an apparatus for visual signaling with lights or mechanically moving arms
   type of:

   apparatus, setup

   equipment designed to serve a specific function
2. verb

   send signals by or as if by semaphore
   type of:

   sign, signal, signalise, signalize

   communicate silently and non-verbally by signals or signs
3. verb

   convey by semaphore, of information
   type of:

   communicate, intercommunicate

   transmit thoughts or feelings