spotter

• POS: Noun
• HYPHEN: spot=ter

CIDE DICTIONARY

spotter, n. 

 One who spots.  [1913 Webster]

OXFORD DICTIONARY

spotter, n.
1 (often in comb.) a person who spots people or things (train-spotter).
2 an aviator or aircraft employed in locating enemy positions etc.

THESAURUS

spotter

Argus, CIA man, Charley, airplane spotter, beagle, cloak-and-dagger operative, counterintelligence agent, counterspy, dick, double agent, espionage agent, eye, fire patrolman, fire warden, fireguard, flatfoot, forward observer, gumshoe, gumshoe man, hawkshaw, inside man, intelligence agent, lookout, lookout man, military-intelligence man, naval-intelligence man, night watchman, operative, patrol, patroller, patrolman, picket, private eye, reconnoiterer, roundsman, scout, secret agent, sentinel, sentry, skip tracer, sleuthhound, spy, spy-catcher, tec, undercover man, vedette, watch, watcher, watchkeeper, watchman