signalとは 意味・読み方・使い方

別の表記

• signall

語源

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). Doublet of signum and sign.

発音

• enPR: sĭgʹnəl, IPA: /ˈsɪɡnəl/
• 韻: -ɪɡnəl
• ハイフネーション: sig‧nal

名詞

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.
   1. A railway signal.
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.

   • 2023, Róisín Murphy, “Hurtz So Bad”, in Hit Parade:

     Did I get it wrong all along? / You were sending signals / You sent certain signals to me

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

反意語

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

派生語

関連する語

参考

• tocsin

動詞

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

1. (ambitransitive) To indicate; to convey or communicate by a signal.

   Hyponyms: signpost, telegraph

   I signalled my acquiescence with a nod.

   He whistled to signal that we should stop.

   My arms wheeled frantically in the air as I tried to signal for help.

   • 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.

   • 2025 April 21, Peter Stanford, “Pope Francis obituary”, in The Guardian‎, archived from the original on 26 July 2025:

     The break with tradition that Francis, who has died aged 88 after suffering from double pneumonia, represented even managed to trump the shock value of the resignation of Benedict, who was the first pope for 600 years to take that option rather than die in office. Immediately, Bergoglio signalled unambiguously that he intended to be a different kind of pope, one for the 21st century.

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

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

派生語

形容詞

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, 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.

同意語

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

派生語

関連する語

• signature (adjective)

アナグラム

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