spotter
Concise Oxford English Dictionary © 2008 Oxford University Press:
spotter/ˈspɒtə(r)/
▶noun
- 1 [usu. in combination] a person who observes or looks for a particular thing as a hobby or job: bus-spotters.
- 2 an aviator or aircraft employed in spotting enemy positions.
'spotter' also found in these Oxford entries:

