noun a token; an indication; a foreshadowing; a sign.
2. signal ·vt to communicate by signals; as, to signal orders.
3. signal ·vt to notify by a signals; to make a signal or signals to; as, to signal a fleet to anchor.
4. signal ·adj of or pertaining to signals, or the use of signals in conveying information; as, a signal flag or officer.
5. signal ·adj noticeable; distinguished from what is ordinary; eminent; remarkable; memorable; as, a signal exploit; a signal service; a signal act of benevolence.
6. signal ·noun 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.