signal, signaling, sign -- (any nonverbal action or gesture that encodes a message; "signals from the boat suddenly stopped")
signal -- (any incitement to action; "he awaited the signal to start"; "the victory was a signal for wild celebration")
signal -- (an electric quantity (voltage or current or field strength) whose modulation represents coded information about the source from which it comes)
Overview of verb signal
The verb signal has 2 senses
sign, signal, signalize, signalise -- (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")
bespeak, betoken, indicate, point, signal -- (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")
Overview of adj signal
The adj signal has 1 sense
signal -- (notably out of the ordinary; "the year saw one signal triumph for the Labour party")