A person who looks out or observes; an observer; a scout; a watchman; (also) a person who makes an inspection or examination of something. Obsolete.

One who spies upon or watches a person or persons secretly; a secret agent whose business it is to keep a person, place, etc., under close…

A person employed to collect information, esp. with regard to an enemy, or an enemy's country; a scout; a spy. Obsolete.

One who watches; a look-out man; †a spy.

A detective, informer, or spy. Obsolete.

One who keeps watch upon the actions of another; a watchman. †Formerly often in opprobrious sense: A mean spy, a ‘sneak’: cf. scout, n.2 Also spec.…

transferred, and with allusion to the insect's finding its way into the most private places: A spy (cf. French mouche). Obsolete.

A listener; an eavesdropper; a spy.

In extended use: a spy. Obsolete.

One who loiters or lies hidden in a suspicious manner; a spy.

slang. A spy, a detective. Also: a group of (esp. undercover) detectives or police officers.