[ sem-uh-fawr, -fohr ]
See synonyms for semaphore on
  1. an apparatus for conveying information by means of visual signals, as a light whose position may be changed.

  2. any of various devices for signaling by changing the position of a light, flag, etc.

  1. a system of signaling, especially a system by which a special flag is held in each hand and various positions of the arms indicate specific letters, numbers, etc.

verb (used with or without object),sem·a·phored, sem·a·phor·ing.
  1. to signal by semaphore or by some system of flags.

Origin of semaphore

First recorded in 1810–20; from French sémaphore, from Greek sêma “sign”; see -phore

Other words from semaphore

  • sem·a·phor·ic [sem-uh-fawr-ik, -for-], /ˌsɛm əˈfɔr ɪk, -ˈfɒr-/, sem·a·phor·i·cal, adjective
  • sem·a·phor·i·cal·ly, adverb

Words Nearby semaphore Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use semaphore in a sentence

  • "Capital idea—semaphore—clever fellow, Jack," shouted Brand.

    The Pillar of Light | Louis Tracy

British Dictionary definitions for semaphore


/ (ˈsɛməˌfɔː) /

  1. an apparatus for conveying information by means of visual signals, as with movable arms or railway signals, flags, etc

  2. a system of signalling by holding a flag in each hand and moving the arms to designated positions to denote each letter of the alphabet

  1. to signal (information) by means of semaphore

Origin of semaphore

C19: via French, from Greek sēma a signal + -phore

Derived forms of semaphore

  • semaphoric (ˌsɛməˈfɒrɪk) or semaphorical, adjective
  • semaphorically, adverb

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012