Definition of: signal

(sig′nəl) noun
1. A sign or means of communication agreed upon or understood, and used to convey information or command, as at a distance.
2. Telecom. A radio wave or electric current which transmits intelligence, whether direct or in code.
3. An event that incites to action or movement.
4. In some card games, a lead or play that conveys certain information to one's partner. See synonyms under SIGN.
—adjective
1. Distinguished by some special sign or characteristic; notable; conspicuous.
2. Used to signal; a signal fire. See synonyms under EMINENT, EXTRAORDINARY.
—v. ·naled or ·nalled, ·nal·ing or ·nal·ling v.t.
1. To make signals to; inform or notify by signals.
2. To communicate by signals.
—v.i.
3. To make a signal or signals. [<F <L signalis <signum sign]
—sig′nal·er or sig′·nal·ler noun