/ ˈsɪgnəl; NAmE / noun , verb , adjective
■ noun
1.
a movement or sound that you make to give sb information, instructions, a warning, etc.
SYN sign :
a danger / warning / distress etc. signal
At an agreed signal they left the room.
The siren was a signal for everyone to leave the building.
When I give the signal , run!
( NAmE )
All I get is a busy signal when I dial his number (= his phone is being used) .
hand signals (= movements that cyclists and drivers make with their hands to tell other people that they are going to stop, turn, etc.)
—see also turn signal
2.
an event, an action, a fact, etc. that shows that sth exists or is likely to happen
SYN indication :
The rise in inflation is a clear signal that the government's policies are not working.
Chest pains can be a warning signal of heart problems.
Reducing prison sentences would send the wrong signals to criminals.
➡ note at sign
3.
a piece of equipment that uses different coloured lights to tell drivers to go slower, stop, etc., used especially on railways / railroads and roads :
traffic signals
a stop signal
4.
a series of electrical waves that carry sounds, pictures or messages, for example to a radio or television :
TV signals
a high frequency signal
a radar signal
to detect / pick up signals
to emit a signal
■ verb ( -ll- , US -l- )
1.
signal (to sb) to make a movement or sound to give sb a message, an order, etc. :
[ v ]
Don't fire until I signal.
Did you signal before you turned right?
He signalled to the waiter for the bill.
[ vn ]
The referee signalled a foul.
[ v ( that )]
She signalled (that) it was time to leave.
[ v to inf ]
He signalled to us to join him.
[ vn to inf ]
She signalled him to follow.
[ v wh- ]
You must signal which way you are going to turn.
2.
[ vn ] to be a sign that sth exists or is likely to happen
SYN indicate :
This announcement signalled a clear change of policy.
The scandal surely signals the end of his political career.
3.
to do sth to make your feelings or opinions known :
[ vn ]
He signalled his discontent by refusing to vote.
[ v ( that )]
She has signalled (that) she is willing to stand as a candidate.
■ adjective
[ only before noun ] ( formal ) important :
a signal honour
► sig·nal·ly / -nəli; NAmE / adverb :
They have signally failed to keep their election promises.
••
WORD ORIGIN
verb and noun late Middle English : from Old French , from medieval Latin signale , neuter of late Latin signalis , from Latin signum mark, token. The verb dates from the early 19th cent.
adjective early 17th cent.: from French signalé , from the Italian past participle segnalato distinguished, made illustrious, from segnale a signal.