semaphore
UK /ˈsɛm.əˌfɔː/ · US /ˈsɛm.əˌfoɹ/ noun, verb
Forms semaphores semaphoring semaphored
- noun 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.
- noun 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.
- noun (programming) 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. “The thread increments the semaphore to prevent other threads from entering the critical section at the same time.”
- verb (ambitransitive, figurative) To signal using, or as if using, a semaphore, with the implication that it is done nonverbally.
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.
Webster’s 1913
- noun A signal telegraph; an apparatus for giving signals by the disposition of lanterns, flags, oscillating arms, etc.
Etymology [Gr. sémaphore.]
Sources: Wiktionary · Webster’s 1913 — from the Wiktionary entry “semaphore”, CC BY-SA 4.0. Details