follow Dictionary.com

11 Trending Words of 2014

semaphore

[sem-uh-fawr, -fohr] /ˈsɛm əˌfɔr, -ˌfoʊr/
noun
1.
an apparatus for conveying information by means of visual signals, as a light whose position may be changed.
2.
any of various devices for signaling by changing the position of a light, flag, etc.
3.
a system of signaling, especially a system by which a special flag is held in each hand and various positions of the arms indicate specific letters, numbers, etc.
verb (used with object), verb (used without object), semaphored, semaphoring.
4.
to signal by semaphore or by some system of flags.
Origin
1810-1820
1810-20; < Greek sêma sign + -phore
Related forms
semaphoric
[sem-uh-fawr-ik, -for-] /ˌsɛm əˈfɔr ɪk, -ˈfɒr-/ (Show IPA),
semaphorical, adjective
semaphorically, adverb
Dictionary.com Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
Cite This Source
Examples from the web for semaphore
  • In original form, the turn signals were not blinking lamps, but lighted semaphore arms that flipped out from the side pillars.
  • Bloggers and tweeters are quoted freely as semaphore from the streets.
  • The brow has evolved further into a semaphore of fashion awareness.
  • Her eyes can be opened and closed, but not enough to semaphore messages.
  • Everyone, principal singers included, engages in a kind of formal semaphore of hands and arms.
  • Yet another driver extended his entire arm out the bus and used his entire appendage to semaphore a friendly greeting.
British Dictionary definitions for semaphore

semaphore

/ˈsɛməˌfɔː/
noun
1.
an apparatus for conveying information by means of visual signals, as with movable arms or railway signals, flags, etc
2.
a system of signalling by holding a flag in each hand and moving the arms to designated positions to denote each letter of the alphabet
verb
3.
to signal (information) by means of semaphore
Derived Forms
semaphoric (ˌsɛməˈfɒrɪk), semaphorical, adjective
semaphorically, adverb
Word Origin
C19: via French, from Greek sēma a signal + -phore
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Cite This Source
Word Origin and History for semaphore
n.

"apparatus for signaling," 1816, probably via French sémaphore, literally "a bearer of signals," ultimately from Greek sema "sign, signal" (see semantic) + phoros "bearer," from pherein "to carry" (see infer). Related: Semaphoric (1808).

Online Etymology Dictionary, © 2010 Douglas Harper
Cite This Source
semaphore in Technology
programming, operating system
The classic method for restricting access to shared resources (e.g. storage) in a multi-processing environment. They were invented by Dijkstra and first used in T.H.E operating system.
A semaphore is a protected variable (or abstract data type) which can only be accessed using the following operations:
P(s) Semaphore s; while (s == 0) ; /* wait until s&gt;0 */ s = s-1;
V(s) Semaphore s; s = s+1;
Init(s, v) Semaphore s; Int v; s = v;
P and V stand for Dutch "Proberen", to test, and "Verhogen", to increment. The value of a semaphore is the number of units of the resource which are free (if there is only one resource a "binary semaphore" with values 0 or 1 is used). The P operation busy-waits (or maybe sleeps) until a resource is available whereupon it immediately claims one. V is the inverse, it simply makes a resource available again after the process has finished using it. Init is only used to initialise the semaphore before any requests are made. The P and V operations must be indivisible, i.e. no other process can access the semaphore during the their execution.
To avoid busy-waiting, a semaphore may have an associated queue of processes (usually a FIFO). If a process does a P on a semaphore which is zero the process is added to the semaphore's queue. When another process increments the semaphore by doing a V and there are tasks on the queue, one is taken off and resumed.
(1995-02-01)
The Free On-line Dictionary of Computing, © Denis Howe 2010 http://foldoc.org
Cite This Source

Word of the Day

Difficulty index for semaphore

Some English speakers likely know this word

Word Value for semaphore

16
17
Scrabble Words With Friends

Nearby words for semaphore