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 Her eyes blaze, her dancing reads as semaphore; a feeling of overkill, unsettling but necessary, pervades her every move. Dan Piepenbring, Harper’s Magazine , 18 Jan. 2022 It’s not a sentimental picture, but the gestures are intuitive, eloquent, easily read—an elemental semaphore of the human capacity to comfort. Margaret Talbot, The New Yorker, 9 Sep. 2021 The main difference with this method is how the semaphore is initialized. Jacek Krywko, Ars Technica, 2 Oct. 2020 Predictably, this area was a resource locked with a mutex semaphore. Jacek Krywko, Ars Technica, 2 Oct. 2020 The dollar, which has fallen by 6% against a basket of currencies since March, is usually part of the semaphore. The Economist, 11 June 2020 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, 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, 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, 3 Oct. 2019 Recent Examples on the Web: Verb Poorly directed, singers semaphore conventional, unconvincing theatrical gestures that turn them right back into stock opera characters. Los Angeles Times, 20 Sep. 2021 The movie needs Winslet and Ronan’s skills, their ability to semaphore more with sliding glances and tiny gestures than many actors manage with pages of dialogue. Jeannette Catsoulis, New York Times, 12 Nov. 2020 One of the many things the halted meteorological data gathering couldn’t do on such occasions was release the mutex semaphore to the high-priority bus management task. Jacek Krywko, Ars Technica, 2 Oct. 2020 See More

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.

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

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Time Traveler for semaphore

Time Traveler

The first known use of semaphore was in 1815

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Dictionary Entries Near semaphore



semaphore plant

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Statistics for semaphore

Cite this Entry

“Semaphore.” Dictionary, Merriam-Webster, Accessed 29 May. 2022.

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More Definitions for semaphore


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


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