spotter
spot-ter
noun
A person who assists a weightlifter, ensuring safety during heavy lifts.
"His spotter helped him rack the barbell safely."
noun
A person who observes and identifies specific things, often as a hobby.
"The bird spotter saw a rare peregrine falcon."
Thesaurus
Synonyms: scout, sentinel, picket, watch, lookout, sentry, finder, discoverer