Pronunciation: (sig'nl), [key]
—n., adj., v., -naled, -nal•ingor (esp. Brit.) -nalled, -nal•ling.
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.
1. to make a signal to.
2. to communicate or make known by a signal.
to make communication by a signal or signals.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.