signal

signal is a Noun

Definition:

[1] A sign made for the purpose of giving notice to a person of some occurence, command, or danger; also, a sign, event, or watchword, which has been agreed upon as the occasion of concerted action. All obeyed The wonted signal and superior voice Of this great potentate. Milton.

[2] A token; an indication; a foreshadowing; a sign. The weary sun . . . Gives signal of a goodly day to-morrow. Shak. There was not the least signal of the calamity to be seen. De Foc.