signal

/ˈsɪgnəl/

/ˈsɪgnəl/

Other forms: signals; signaled; signalled; signalling

A signal is a gesture or message that people use to communicate with each other. The wave you give a good friend to call her over from across the room and the impulse that transmits your voice through the telephone to your mother are both signals.

In the course of a single day, you probably send and receive thousands of different signals. When you want to cross the street, you wait for the green light — a signal that it's safe to cross. If you're in a relationship and you're not sure whether you like the person you're dating, you could be sending mixed signals — first acting like you're interested, and then acting uninterested. If your date finally gets tired of your mixed signals while you're at a restaurant, you'll need to signal to your server that it's time for the check.

Definitions of signal

1. noun

   any action or gesture that encodes a message
   “signals from the boat suddenly stopped”

   synonyms: sign, signaling

   types:

   recording

   a signal that encodes something (e.g., picture or sound) that has been recorded

   number, phone number, telephone number

   the number is used in calling a particular telephone

   start, starting signal

   a signal to begin (as in a race)

   storm signal

   a signal announcing the approach of a storm (particularly a storm of marked violence)

   beam, radio beam

   a signal transmitted along a narrow path; guides airplane pilots in darkness or bad weather

   ticktack

   system of signalling by hand signs used by bookmakers at racetracks

   time signal

   a signal (especially electronic or by radio) indicating the precisely correct time

   dog-ear

   a corner of a page turned down to mark your place

   animal communication

   communication between animals (of the same species)

   alarm, alarum, alert, warning signal

   an automatic signal (usually a sound) warning of danger

   distress call, distress signal

   an internationally recognized signal sent out by a ship or plane indicating that help is needed

   all clear

   a signal (usually a siren) that danger is over

   bugle call

   a signal broadcast by the sound of a bugle

   curfew

   a signal (usually a bell) announcing the start of curfew restrictions

   retreat

   (military) a signal to begin a withdrawal from a dangerous position

   drumbeat

   (military) the beating of a drum as a signal for lowering the flag at sundown

   radiotelegraphic signal, telegraphic signal

   a signal transmitted by telegraphy

   whistle, whistling

   the act of signalling (e.g., summoning) by whistling or blowing a whistle

   high sign

   a silent signal of warning or recognition

   symbol

   an arbitrary sign (written or printed) that has acquired a conventional significance

   visual signal

   a signal that involves visual communication

   indicator

   a signal for attracting attention

   electronic signal

   a signal generated by electronic means

   radio beacon

   a characteristic signal emitted by a transmitter used for navigation

   input, input signal

   signal going into an electronic system

   output, output signal

   signal that comes out of an electronic system

   bologram, bolograph

   record or recording made by a bolometer

   chromatogram

   the recording (column or paper strip) on which the constituents of a mixture are adsorbed in chromatography

   oscillogram

   the recording produced by an oscillograph

   spirogram

   a recording of breathing made with a spirograph

   torpedo

   a small explosive device that is placed on a railroad track and fires when a train runs over it; the sound of the explosion warns the engineer of danger ahead

   stock symbol

   the letters used to identify listed companies on the securities exchanges where they are traded

   accolade, award, honor, honour, laurels

   a tangible symbol signifying approval or distinction

   storm cone

   a canvas cone hoisted to warn of high winds

   brand, mark, stain, stigma

   a symbol of disgrace or infamy

   item, token

   an individual instance of a type of symbol

   type

   all of the tokens of the same symbol

   birdcall, birdsong, call, song

   the characteristic sound produced by a bird

   air alert

   the warning signal that begins a period of preparation for an enemy air attack

   burglar alarm

   a loud warning signal produced by a burglar alarm

   SOS

   an internationally recognized distress signal in radio code

   Mayday

   an internationally recognized distress signal via radiotelephone (from the French m'aider)

   recall

   a bugle call that signals troops to return

   lights-out, taps

   (military) signal to turn the lights out

   reveille, wake-up signal

   (military) signal to wake up

   retreat

   (military) a bugle call signaling the lowering of the flag at sunset

   tattoo

   a drumbeat or bugle call that signals the military to return to their quarters

   dit, dot

   the shorter of the two telegraphic signals used in Morse code

   dah, dash

   the longer of the two telegraphic signals used in Morse code

   nose

   a symbol of inquisitiveness

   number, numeral

   a symbol used to represent a number

   symbolism

   a system of symbols and symbolic representations

   lingam

   the Hindu phallic symbol of Siva

   pound, pound sign

   a symbol for a unit of currency (especially for the pound sterling in Great Britain)

   printed symbol, written symbol

   a written or printed symbol

   dollar, dollar mark, dollar sign

   a symbol of commercialism or greed

   monogram

   a graphic symbol consisting of 2 or more letters combined (usually your initials); printed on stationery or embroidered on clothing

   impression, stamp

   a symbol that is the result of printing or engraving

   watch fire

   a fire lighted at night as a signal

   light

   a visual warning signal

   red light, warning light

   a cautionary sign of danger

   flare, flash

   a burst of light used to communicate or illuminate

   flag, signal flag

   a rectangular piece of fabric used as a signalling device

   mantle

   the cloak as a symbol of authority

   Crown

   the Crown (or the reigning monarch) as the symbol of the power and authority of a monarchy

   air sock, air-sleeve, drogue, sock, wind cone, wind sleeve, wind sock, windsock

   a truncated cloth cone mounted on a mast; used (e.g., at airports) to show the direction of the wind

   post, stake

   a pole or stake set up to mark something (as the start or end of a race track)

   point of reference, reference, reference point

   an indicator that orients you generally

   blinker, trafficator, turn indicator, turn signal

   a blinking light on a motor vehicle that indicates the direction in which the vehicle is about to turn

   armband

   worn around arm as identification or to indicate mourning

   skyrocket

   propels bright light high in the sky, or used to propel a lifesaving line or harpoon

   radar echo

   an electronic signal that has been reflected back to the radar antenna; contains information about the location and distance of the reflecting object

   racon, radar beacon

   a device that, on receiving radar signals, transmits coded signals in response to help navigators determine their position

   beacon, beacon fire

   a fire (usually on a hill or tower) that can be seen from a distance

   printout

   the output of a computer in printed form

   read-out, readout

   the output of a computer in readable form

   fire alarm

   a shout or bell to warn that fire has broken out

   foghorn, fogsignal

   a loud low warning signal that can be heard by fogbound ships

   horn

   a noise made by the driver of an automobile to give warning;

   red flag

   a flag that serves as a warning signal

   siren

   a warning signal that is a loud wailing sound

   alarm bell, tocsin

   the sound of an alarm (usually a bell)

   brake light, stoplight

   a red light on the rear of a motor vehicle that signals when the brakes are applied to slow or stop

   barber's pole

   striped pole outside a barbershop

   staff

   a rod carried as a symbol

   icon

   (computer science) a graphic symbol (usually a simple picture) that denotes a program or a command or a data file or a concept in a graphical user interface

   insignia, mark, marker, marking

   a distinguishing symbol

   identifier

   a symbol that establishes the identity of the one bearing it

   variable

   a symbol (like x or y) that is used in mathematical or logical expressions to represent a variable quantity

   glyph

   a small, often stylized graphic symbol

   type of:

   communication

   something that is communicated by or to or between people or groups
2. noun

   any incitement to action
   “he awaited the signal to start”

   “the victory was a signal for wild celebration”

   type of:

   incitation, incitement, provocation

   something that incites or provokes; a means of arousing or stirring to action
3. noun

   an electric quantity (voltage or current or field strength) whose modulation represents coded information about the source from which it comes
   types:

   interrupt

   a signal that temporarily stops the execution of a program so that another procedure can be carried out

   type of:

   electrical energy, electricity

   energy made available by the flow of electric charge through a conductor
4. adjective

   notably out of the ordinary
   “the year saw one signal triumph for the Labour party”

   synonyms:

   impressive

   making a strong or vivid impression
5. verb

   communicate by means of an action, gesture, or sound
   “The diner signaled the waiters to bring the menu”

   synonyms: sign, signalise, signalize

   types:

   wigwag

   signal by or as if by a flag or light waved according to a code

   semaphore

   send signals by or as if by semaphore

   heliograph

   signal by means of a mirror and the using the sun's rays

   flag

   communicate or signal with a flag

   whistle

   give a signal by whistling

   type of:

   communicate, intercommunicate

   transmit thoughts or feelings
6. verb

   be a signal for or a symptom of
   “The economic indicators signal that the euro is undervalued”

   synonyms: bespeak, betoken, indicate, point

   types:

   augur, auspicate, betoken, bode, forecast, foreshadow, foretell, omen, portend, predict, prefigure, presage, prognosticate

   indicate by signs

   mark

   designate as if by a mark

   threaten

   to be a menacing indication of something:"The clouds threaten rain"

   blaze

   indicate by marking trees with blazes

   dimension

   indicate the dimensions on

   signpost

   mark with a signpost, as of a path

   distinguish, signalise, signalize

   make conspicuous or noteworthy

   buoy

   mark with a buoy

   foreshow

   foretell by divine inspiration

   type of:

   tell

   let something be known