definition of
signal

[1] #1 signal n. [signaling, sign] any nonverbal action or gesture that encodes a message; "signals from the boat suddenly stopped". wn

[2] #2 signal v. [sign, 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". wn

[3] #3 signal v. [bespeak, betoken, indicate, point] 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". wn

[4] #4 signal n. any incitement to action; "he awaited the signal to start"; "the victory was a signal for wild celebration". wn

[5] #5 signal s. notably out of the ordinary; "the year saw one signal triumph for the Labour party". wn