To watch secretly or covertly; to surveil.

(intransitive) To act as a spy. / (transitive) To spot; to catch sight of. / (intransitive) To search narrowly; to scrutinize.

A person who secretly watches and examines the actions of other individuals or organizations and gathers information on them (usually to gain an advantage).

Obsolete spelling of spied; simple past tense and past participle of spy

espionage; the act of secretly gathering information

present participle of spy

plural of spying

(games) A game where players have to guess what one can see, based on the initial letter of the object. / (games, archaic) A children's game of hide and seek, so called from the cry when one is found.

(Ireland, Catholicism) Holy Wednesday

A network of spies.