noun · verb · 7 senses · updated from the 2026-07-25 local source snapshot
Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.
Sound
Pronunciation
Each Play button uses your device's default local English voice, or a natural local fallback. The selected voice name appears after playback. This is synthesized speech, not a source recording.
Received-Pronunciation:/ˈsɛm.əˌfɔː/
Received-Pronunciation:Recorded audio is listed in the source snapshot.
General-American:/ˈsɛm.əˌfoɹ/
1
noun
Meaning 1
Any equipment used for visual signalling by means of flags, lights, or mechanically moving arms, which are used to represent letters of the alphabet, or words.
Definition source: English Wiktionary via Wiktextract
Usage: countable, uncountable
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
2
noun
Meaning 2
A visual system for transmitting information using the above equipment; especially, by means of two flags held one in each hand, using an alphabetic and numeric code based on the position of the signaller's arms; flag semaphore.
Definition source: English Wiktionary via Wiktextract
Usage: countable, uncountable
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
3
noun
Meaning 3
A bit, token, fragment of code, or some other mechanism which is used to restrict access to a shared function or device to a single process at a time, or to synchronize and coordinate events in different processes.
Definition source: English Wiktionary via Wiktextract
The thread increments the semaphore to prevent other threads from entering the critical section at the same time.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
4
verb
Meaning 4
To signal using, or as if using, a semaphore, with the implication that it is done nonverbally.
Definition source: English Wiktionary via Wiktextract
Usage: ambitransitive, figuratively
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
5
noun
Meaning 5
an apparatus for visual signaling with lights or mechanically moving arms
Definition source: Princeton WordNet 3.0
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
Broader terms: apparatus, setup
6
verb
Meaning 6
convey by semaphore, of information
Definition source: Princeton WordNet 3.0
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
Broader terms: communicate, intercommunicate
7
verb
Meaning 7
send signals by or as if by semaphore
Definition source: Princeton WordNet 3.0
No example sentence was provided for this meaning.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
Broader terms: sign, signal, signalize, signalise
History
Etymology
The noun is borrowed from French sémaphore, from Ancient Greek σῆμα (sêma, “mark, sign, token”) + French -phore (from Ancient Greek -φόρος (-phóros, suffix indicating a bearer or carrier)). By surface analysis, sema- + -phore. The verb is derived from the noun.
Across languages
Translations
45 source translations are retained for this English entry.
Finnish:
opastin
— equipment used for visual signalling
Romanian:
semafor
— equipment used for visual signalling
Russian:
семафо́р
(semafór)
— equipment used for visual signalling
Armenian:
լուսազդանշան
(lusazdanšan)
— visual system for transmitting information
Belarusian:
семафо́р
(sjemafór)
— visual system for transmitting information
Belarusian:
святлафо́р
(svjatlafór)
— visual system for transmitting information
Bulgarian:
семафо́р
(semafór)
— visual system for transmitting information
Catalan:
semàfor
— visual system for transmitting information
Chinese Mandarin:
旗語 /旗语
(qíyǔ)
— visual system for transmitting information
Czech:
semafor
— visual system for transmitting information
Dutch:
semafoor
— visual system for transmitting information
Finnish:
opastin
— visual system for transmitting information
Finnish:
opastinjärjestelmä
— visual system for transmitting information
Hebrew:
סמפור
(semafor)
— visual system for transmitting information
Hungarian:
szemafor
— visual system for transmitting information
Italian:
semaforo
— visual system for transmitting information
Russian:
семафо́р
(semafór)
— visual system for transmitting information
Serbo-Croatian:
се̏мафо̄р
— visual system for transmitting information
Serbo-Croatian:
sȅmafōr
— visual system for transmitting information
Spanish:
semáforo
— visual system for transmitting information
Ukrainian:
семафо́р
(semafór)
— visual system for transmitting information
Dutch:
semafoor
— visual system for transmitting information using flags
Finnish:
lippuviittoilu
— visual system for transmitting information using flags
Hebrew:
סמפור
(semafor)
— visual system for transmitting information using flags
Italian:
semaforo marittimo
— visual system for transmitting information using flags
Japanese:
手旗信号
(tebata shingō)
— visual system for transmitting information using flags
Russian:
флажко́вая сигнализа́ция
(flažkóvaja signalizácija)
— visual system for transmitting information using flags
Czech:
semafor
— mechanism used to restrict access to a shared function or device to a single process at a time
Dutch:
semafoor
— mechanism used to restrict access to a shared function or device to a single process at a time
Finnish:
semafori
— mechanism used to restrict access to a shared function or device to a single process at a time
French:
sémaphore
— mechanism used to restrict access to a shared function or device to a single process at a time
German:
Semaphor
— mechanism used to restrict access to a shared function or device to a single process at a time
Greek:
σηματοφόρος
(simatofóros)
— mechanism used to restrict access to a shared function or device to a single process at a time
Hebrew:
סמפור
(semafor)
— mechanism used to restrict access to a shared function or device to a single process at a time
Icelandic:
veif
— mechanism used to restrict access to a shared function or device to a single process at a time
Japanese:
セマフォ
(semafo)
— mechanism used to restrict access to a shared function or device to a single process at a time
Polish:
semafor
— mechanism used to restrict access to a shared function or device to a single process at a time
Russian:
семафо́р
(semafór)
— mechanism used to restrict access to a shared function or device to a single process at a time
Swedish:
semafor
— mechanism used to restrict access to a shared function or device to a single process at a time
Turkish:
semafor
— mechanism used to restrict access to a shared function or device to a single process at a time
Dutch:
signaleren
— to signal using, or as if using, a semaphore
Dutch:
seinen
— to signal using, or as if using, a semaphore
Finnish:
viittoa
— to signal using, or as if using, a semaphore
Spanish:
semáforo
— to signal using, or as if using, a semaphore
Swedish:
semaforera
— to signal using, or as if using, a semaphore
