semaphore definition by Webster's New World
- 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: French sémaphore ; from Classical Greek sēma, sign (see semantic) plush -phoros: see -phore
semaphore definition by American Heritage Dictionary
- 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.
Origin: Greek sēma, sign + -phore.
- semˌa·phorˈic adjective
- semˌa·phorˈi·cal·ly adverb
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.