sem·​a·​phore | \ ˈse-mə-ˌfȯr How to pronounce semaphore (audio) \

Definition of semaphore

 (Entry 1 of 2)

1 : an apparatus for visual signaling (as by the position of one or more movable arms)
2 : a system of visual signaling by two flags held one in each hand


semaphored; semaphoring

Definition of semaphore (Entry 2 of 2)

transitive verb

: to convey (information) by or as if by semaphore

intransitive verb

: to send signals by or as if by semaphore

Illustration of semaphore

Illustration of semaphore


semaphore 2: alphabet; 3 positions following Z: error, end of word, numerals follow; numerals 1, 2, 3, 4, 5, 6, 7, 8, 9, 0 same as A through J

In the meaning defined above

Examples of semaphore in a Sentence

Recent Examples on the Web: Noun One dancer executed a series of semaphore-like movements, which the dancer on the next roof over tried to copy exactly, and so on down the line. Brian Seibert, New York Times, "A Home Version of Trisha Brown’s ‘Roof Piece,’ No Roof Required," 7 Apr. 2020 Giotto’s figures make simple, resonant gestures that are at once hauntingly isolated — like private semaphores — and vital markers in an unfolding communal narrative. Washington Post, "Bathers With a Turtle, 1907-08," 26 Feb. 2020 The truck hit the rear of the car, rolled onto its side, left the road and hit a semaphore light. Nick Ferraro, Twin Cities, "State Patrol investigating crash that killed 22-year-old woman in Inver Grove Heights; second fatality at intersection since mid-August," 3 Oct. 2019 Some of our fleeing units had hauled even more frozen Russian bodies out of the woods and propped them upright, their arms stilled in various eerie semaphore. Arna Bontemps Hemenway, The Atlantic, "Wolves of Karelia," 19 July 2019 At their disposal are agreed-upon symbols and semaphores. Rick Paulas, Popular Mechanics, "The Graffiti That Will Save Your Life," 22 Feb. 2016 Customers should be advised to bring semaphores in order to gain the attention of the waitstaff, which seems unaccustomed to any action at all and slightly bemused to encounter actual humans in their midst. Fox, Town & Country, "A Table for Mr. Fox," 21 Nov. 2012 At one point, six of them line up front to back and do a kind of semaphore. Jeffrey Gantz,, "Boston Ballet opens with high-octane ‘Parts in Suite’," 11 Mar. 2018 Aquatic extinctions happen silently, beneath the surface, lacking any clear semaphore. Nick Pyenson, Smithsonian, "There Are Possibly Only 30 of These Rare Porposies Left on the Planet," 26 Oct. 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'semaphore.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of semaphore


1815, in the meaning defined at sense 1


1838, in the meaning defined at transitive sense

History and Etymology for semaphore


Greek sēma sign, signal + International Scientific Vocabulary -phore

Keep scrolling for more

Learn More about semaphore

Time Traveler for semaphore

Time Traveler

The first known use of semaphore was in 1815

See more words from the same year

Statistics for semaphore

Last Updated

24 May 2020

Cite this Entry

“Semaphore.” Dictionary, Merriam-Webster, Accessed 29 May. 2020.

Keep scrolling for more

More Definitions for semaphore


How to pronounce semaphore (audio)

English Language Learners Definition of semaphore

: a system used for sending signals by using two flags that are held in your hands


sem·​a·​phore | \ ˈse-mə-ˌfȯr How to pronounce semaphore (audio) \

Kids Definition of semaphore

1 : a device for sending signals that can be seen by the receiver
2 : a system of sending signals with two flags held one in each hand

Keep scrolling for more

Comments on semaphore

What made you want to look up semaphore? Please tell us where you read or heard it (including the quote, if possible).


See Definitions and Examples »

Get Word of the Day daily email!

Test Your Vocabulary

May 2020 Words of the Day Quiz

  • a blooming wisteria tree
  • Which is a synonym of exiguous?
Spell It

Can you spell these 10 commonly misspelled words?


Test Your Knowledge - and learn some interesting things along the way.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!