spotter

1 ENTRIES FOUND:
spotter /ˈspɑːtɚ/ noun
plural spotters
spotter
/ˈspɑːtɚ/
noun
plural spotters
Britannica Dictionary definition of SPOTTER
[count]
1 
: someone who looks for a particular type of person or thing — see also trainspotter
2 
: a person who watches and helps someone who is exercising in order to help prevent injuries