- any apparatus for signaling, as the arrangement of lights, flags, and mechanical arms on railroads
- a system of signaling by the use of two flags, one held in each hand: the letters of the alphabet are represented by the various positions of the arms
- any system of signaling by semaphore
Origin of semaphoreFrench sémaphore ; from Classical Greek sēma, sign (see semantic) + -phoros: see -phore
- A visual signaling apparatus with flags, lights, or mechanically moving arms, as one used on a railroad.
- A visual system for sending information by means of two flags that are held one in each hand, using an alphabetic code based on the position of the signaler's arms.
tr. & intr.v.sem·a·phored, sem·a·phor·ing, sem·a·phores
Origin of semaphoreGreek sēma, sign + –phore.
top: railroad signal
bottom: flag signal system
- Any visual signaling system with flags, lights, or mechanically moving arms.
- A visual system for transmitting information by means of two flags that are held one in each hand, using an alphabetic and numeric code based on the position of the signaler’s arms.
- (computing) 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.
(third-person singular simple present semaphores, present participle semaphoring, simple past and past participle semaphored)
- (intransitive) To signal using (as if using) a semaphore.
Borrowed in 1816 from French sémaphore, coined in French from Ancient Greek σῆμα (sêma, “sign”), and -φωρος (-phoros, “bearing, bearer”), from φέρω (férō, “to bear, carry”).
semaphore - Computer Definition
(1) A hardware or software flag used to indicate the status of some activity.
(2) A shared space for interprocess communications (IPC) controlled by "wake up" and "sleep" commands. The source process fills a queue and goes to sleep until the destination process uses the data and tells the source process to wake up.