signal2 past tense and past participle signalled, present participle signalling British English, past tense and past participle signaled, present participle signaling American English
1 [intransitive and transitive]
to make a sound or action in order to give information or tell someone to do something:
She signalled, and the waiter brought the bill.
The whistle signalled the end of the match.
Mary signalled wildly at them, but they didn't notice.
The judge signaled to a police officer and the man was led away.
He pushed his plate away and signalled for coffee.
signal (to) somebody to do something
She signalled to the children to come inside.
The bell signaled that school was over.
to make something clear by what you say or do - used in news reports:
Both sides have signaled their willingness to start negotiations.
British sources last night signalled their readiness to talk.
The Prime Minister's speech today signals that there will be a shake-up in the cabinet.
to be a sign that something is going to happen
signal the start/beginning/end of something
the lengthening days that signal the end of winter
to show the direction you intend to turn in a vehicle, using the lights [= indicate American English]
Signal before you pull out.