See more synonyms for signal on
  1. anything that serves to indicate, warn, direct, command, or the like, as a light, a gesture, an act, etc.: a traffic signal; a signal to leave.
  2. anything agreed upon or understood as the occasion for concerted action.
  3. an act, event, or the like that causes or incites some action: The unjust execution was the signal for revolt.
  4. a token; indication.
  5. Electronics. an electrical quantity or effect, as current, voltage, or electromagnetic waves, that can be varied in such a way as to convey information.
  6. Cards. a play that reveals to one's partner a wish that he or she continue or discontinue the suit led.
  1. serving as a signal; used in signaling: a signal flag.
  2. unusual; notable; outstanding: a signal exploit.
verb (used with object), sig·naled, sig·nal·ing or (especially British) sig·nalled, sig·nal·ling.
  1. to make a signal to.
  2. to communicate or make known by a signal.
verb (used without object), sig·naled, sig·nal·ing or (especially British) sig·nalled, sig·nal·ling.
  1. to make communication by a signal or signals.

Origin of signal

1350–1400; Middle English (noun) < Medieval Latin signāle, Late Latin, noun use of neuter of signālis of a sign. See sign, -al2, -al1
Related formssig·nal·er; especially British sig·nal·ler, nounpre·sig·nal, noun, verb (used with object), pre·sig·naled, pre·sig·nal·ing or (especially British) pre·sig·nalled, pre·sig·nal··sig·nal, verb re·sig·naled, re·sig·nal·ing or (especially British) re·sig·nalled, re·sig·nal·ling.un·sig·naled, adjectiveun·sig·nalled, adjective
Can be confusedsignal single

Synonyms for signal

See more synonyms for on Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for signalled

Contemporary Examples of signalled

  • The poll also signalled that Americans were comfortable with targeted military action again Iran in the worst-case scenario.

  • President Obama signalled his move to a middle strategy in his Tuesday meeting with Congressional leaders.

    The Daily Beast logo
    How To Win Afghanistan

    Leslie H. Gelb

    October 5, 2009

Historical Examples of signalled

  • The Patriarch insisted on his staying to dinner, and Flora signalled 'Yes!'

    Little Dorrit

    Charles Dickens

  • They tugged at their gold-braided jackets and signalled the honor guard.

    The Adventurer

    Cyril M. Kornbluth

  • When this was done, he signalled to Brother Andrew to take off the cassock.

    The Christian

    Hall Caine

  • Then he signalled to the mate to fire the culverin of which he had charge.

    The Sea-Hawk

    Raphael Sabatini

  • "If you go you will make me nervous—and the recital is sold out," he signalled.


    James Huneker

British Dictionary definitions for signalled


  1. any sign, gesture, token, etc, that serves to communicate information
  2. anything that acts as an incitement to actionthe rise in prices was a signal for rebellion
    1. a variable parameter, such as a current or electromagnetic wave, by which information is conveyed through an electronic circuit, communications system, etc
    2. the information so conveyed
    3. (as modifier)signal strength; a signal generator
  1. distinguished or conspicuous
  2. used to give or act as a signal
verb -nals, -nalling or -nalled or US -nals, -naling or -naled
  1. to communicate (a message, etc) to (a person)
Derived Formssignaller or US signaler, noun

Word Origin for signal

C16: from Old French seignal, from Medieval Latin signāle, from Latin signum sign
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

Word Origin and History for signalled



late 14c., "visible sign, indication," from Old French signal, seignal "seal, imprint, sign, mark," from Medieval Latin signale "a signal," from Late Latin signalis (adj.) "used as a signal, pertaining to a sign," from Latin signum "signal, sign" (see sign (n.)). Restricted sense "agreed-upon sign (to commence or desist, etc.) is from 1590s. Meaning "modulation of an electric current" is from 1855.



"remarkable, striking, notable" ("serving as a sign"), 1640s, from French signalé, past participle of signaler "to distinguish, signal" (see signal (n.)).



1805, "to make signals to," from signal (n.). Related: Signaled; signaling. Earlier verb was signalize (1650s).

Online Etymology Dictionary, © 2010 Douglas Harper

signalled in Science


  1. A fluctuating quantity or impulse whose variations represent information. The amplitude or frequency of voltage, current, electric field strength, light, and sound can be varied as signals representing information.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.