semaphore

American  

[sem-uh-fawr, -fohr] / ˈsɛm əˌfɔr, -ˌfoʊr /

noun

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.

3. 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.

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verb (used with or without object)

semaphored, semaphoring

1. to signal by semaphore or by some system of flags.

semaphore British  

/ ˌsɛməˈfɒrɪk, ˈsɛməˌfɔː /

noun

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

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verb

1. to signal (information) by means of semaphore

Other Word Forms

• semaphoric
  adjective
• semaphorical
  adjective
• semaphorically
  adverb

Etymology

Origin of semaphore

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

Explanation

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.

Example Sentences

That meant learning semaphore to send messages during the day and Morse code for nighttime communications.

From Seattle Times • May 30, 2024

And do we need so much semaphore to understand our relationships?

From Salon • Jan. 2, 2024

We also found semaphore flags, a vastly outdated way to communicate between units.

From BBC • Feb. 22, 2023

You’ve probably seen the semaphore system where years ago people in uniform waved handheld flags to convey messages.

From Washington Post • Oct. 28, 2022

Edward pushed a door open, and there was the yellow brass bed and the old semaphore banners from college and a very musty raccoon coat which he stroked with muted affection.

From "The Martian Chronicles" by Ray Bradbury

Related Words

• alarm
• beacon
• cue
• gesture
• indicator
• sign