Definition of signal

• n. - 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.
• n. - A token; an indication; a foreshadowing; a sign.
• a. - Noticeable; distinguished from what is ordinary; eminent; remarkable; memorable; as, a signal exploit; a signal service; a signal act of benevolence.
• a. - Of or pertaining to signals, or the use of signals in conveying information; as, a signal flag or officer.
• v. t. - To communicate by signals; as, to signal orders.
• v. t. - To notify by a signals; to make a signal or signals to; as, to signal a fleet to anchor.