IPA: /ˈspɒtə/
KK: /ˈspɑːtər/
A person who looks for or identifies something, often in a specific context like military, security, or cleaning.
The spotter helped the team locate the target during the training exercise.
Spotter → It is formed from "spot" (from Old English *spt*, meaning a mark or point) and "-er" (meaning a person who). A spotter is a person who identifies or marks a specific point or location.
Think of someone who identifies a 'mark' or 'point' — that's what a spotter does, and the '-er' just means a person.