signal

notably out of the ordinary

“the year saw one signal triumph for the Labour party”

any nonverbal action or gesture that encodes a message

“signals from the boat suddenly stopped”

any incitement to action

“he awaited the signal to start”

“the victory was a signal for wild celebration”

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

communicate silently and non-verbally by signals or signs

“He signed his disapproval with a dismissive hand gesture”

“The diner signaled the waiters to bring the menu”

“They signal them the information”

“They signal the information to them”

be a signal for or a symptom of

“These symptoms indicate a serious illness”

“Her behavior points to a severe neurosis”

“The economic indicators signal that the euro is undervalued”