signal

• signall

From Old French segnal, seignal or Medieval Latin signāle; noun use of the neuter of Late Latin signālis, from Latin signum; verb use from 1805, as a shortened from signalize (1650s).

• enPR: sĭgʹnəl, IPA^(key): /ˈsɪɡnəl/

• Audio (US):

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• Rhymes: -ɪɡnəl
• Hyphenation: sig‧nal

signal (plural signals)

1. A sequence of states representing an encoded message in a communication channel.
2. Any variation of a quantity or change in an entity over time that conveys information upon detection.
3. A sign made to give notice of some occurrence, command, or danger, or to indicate the start of a concerted action.
   • 1667, John Milton, “Book V”, in Paradise Lost. […], London: […] [Samuel Simmons], and are to be sold by Peter Parker […]; [a]nd by Robert Boulter […]; [a]nd Matthias Walker, […], →OCLC; republished as Paradise Lost in Ten Books: […], London: Basil Montagu Pickering […], 1873, →OCLC:

     All obeyed / The wonted signal and superior voice / Of this great potentate.

   • 2020 December 30, David Allen, “Unusual signals...”, in Rail, page 64:

     Banner-Repeater signals tend to be provided in locations where drivers receive insufficient warning of the main signal, thereby effectively increasing the sighting distance for the main signal.

4. An on-off light, semaphore, or other device used to give an indication to another person.
5. (of a radio, TV, telephone, internet, etc.) An electromagnetic action, normally a voltage that is a function of time, that conveys the information of the radio or TV program or of communication with another party.

   My mobile phone can't get a signal in the railway station.

6. An action, change or process done to convey information and thus reduce uncertainty.
7. A token; an indication; a foreshadowing; a sign.
   • c. 1593 (date written), William Shakespeare, “The Tragedy of Richard the Third: […]”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, →OCLC, [Act V, scene iii]:

     The weary sun […] / Gives signal of a goodly day to-morrow.

   • 1722, Daniel Defoe, A Journal of the Plague Year:

     There was not the least signal of the calamity to be seen.

8. Useful information, as opposed to noise.
9. (computing, Unix) A simple interprocess communication used to notify a process or thread of an occurrence.
10. (biochemistry) A signalling interaction between cells

• (antonym(s) of “useful information”): noise

• tocsin

signal (third-person singular simple present signals, present participle (UK) signalling or (US) signaling, simple past and past participle (UK) signalled or (US) signaled)

1. (transitive, intransitive) To indicate; to convey or communicate by a signal.

   I signalled my acquiescence with a nod.

   He whistled to signal that we should stop.

   • 1962 June, David Walters, “The new station and layout at Coventry”, in Modern Railways, page 405:

     In order to accommodate the new platform 4 and the reversibly signalled slow line, a deep cutting had to be cut back and held up in places with a concrete retaining wall.

   • 2015, Andy Nottenkamper, A Rule Not Followed:

     I signaled for our waiter and ordered two Glenlivets, the only single malt they had behind the bar.

   • 2024 February 7, Mel Holley, “Network News: LNER ditches Off-Peak for 70min semi-flexible fare”, in RAIL, number 1002, page 6:

     It is the latest step towards an airline-style advance booking-only system, which rail users have denounced as signalling the end of affordable, immediate travel.

2. (transitive) To communicate with (a person or system) by a signal.

   Seeing the flames, he ran to the control room and signalled headquarters.

signal (not comparable)

1. Standing above others in rank, importance, or achievement.

   a signal exploit; a signal success; a signal act of benevolence

   • 1671, John Milton, “Samson Agonistes, […].”, in Paradise Regain’d. A Poem. In IV Books. To which is Added, Samson Agonistes, London: […] J[ohn] M[acock] for John Starkey […], →OCLC, page 27:

     As ſignal now in low dejected ſtate, / As earſt in higheſt, behold him where he lies.

   • 1866, Herman Melville, Battle-Pieces and Aspects of the War‎^[1], Supplement:

     But, setting this view aside, dishonorable would it be in the South were she willing to abandon to shame the memory of brave men who with signal personal disinterestedness warred in her behalf, though from motives, as we believe, so deplorably astray.

• eminent, noteworthy, significant; see also Thesaurus:important or Thesaurus:notable

• signature (adjective)

• Saling, algins, aligns, lasing, liangs, lingas

Other scripts
Cyrillic	сигнал
Roman

Borrowed from Russian сигнал (signal).

• Hyphenation: sig‧nal

signal

1. signal

• “signal”, in Luğatçıq (in Russian)

From Medieval Latin signale.

• IPA^(key): /siˈnæˀl/

signal n (singular definite signalet, plural indefinite signaler)

1. a signal

• “signal” in Den Danske Ordbog

Re-latinization of Old French segnal, from Medieval Latin signale, from Late Latin signālis, from Latin signum.

• IPA^(key): /si.ɲal/

• Audio:

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signal m (plural signaux)

1. signal
   • 1864, Jules Verne, Voyage au centre de la Terre, sourced from [2]:

     Nous verrons bien. C’est le mot du professeur, qui, après avoir baptisé cet îlot volcanique du nom de son neveu, donne le signal de rembarquement.

     "That is what we shall see." So says the Professor, who, having named this volcanic islet after his nephew, gives the signal to embark again.

• écrevisse signal

• signe

• Dutch: signaal, signael (obsolete)
  • → Indonesian: sinyal
• → Turkish: sinyal

• “signal”, in Trésor de la langue française informatisé [Digitized Treasury of the French Language], 2012.

• lignas

From Medieval Latin signale.

signal n (definite singular signalet, indefinite plural signal or signaler, definite plural signala or signalene)

1. a signal

• “signal” in The Bokmål Dictionary.

From Medieval Latin signale.

signal n (definite singular signalet, indefinite plural signal, definite plural signala)

1. a signal

• “signal” in The Nynorsk Dictionary.

Borrowed from French signal.

signal n (plural signale)

1. signal

From German Signal, from Medieval Latin signale, from Latin signum.

• IPA^(key): /sǐɡnaːl/
• Hyphenation: sig‧nal

sìgnāl m (Cyrillic spelling сѝгна̄л)

1. signal

• “signal”, in Hrvatski jezični portal [Croatian language portal] (in Serbo-Croatian), 2006–2024

Derived from Latin signālis, from signum.

• Audio:

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signal c

1. a signal

• signal in Svenska Akademiens ordböcker
• signal in Elof Hellquist, Svensk etymologisk ordbok (1st ed., 1922)

• inslag, ligans, singla, slinga

From Old French segnal, seignal or Medieval Latin signāle, noun use of the neuter of Late Latin signālis, from Latin signum.

• Audio:

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signal n (plural signale)

1. signal

Borrowed from English signal.

signal m (plural signalau or signals, not mutable)

1. signal

   Synonym: arwyddiad

• R. J. Thomas, G. A. Bevan, P. J. Donovan, A. Hawke et al., editors (1950–present), “signal”, in Geiriadur Prifysgol Cymru Online (in Welsh), University of Wales Centre for Advanced Welsh & Celtic Studies