spotter

(spŏtˈər)

1. One that applies spots.
2. One that looks for, locates, and reports something, as:
   a. A military or civil defense lookout.
   b. Informal A person hired to detect dishonest acts by employees, as in a bank.
3. Sports
   a. One who identifies players on the field, as for a radio or television announcer.
   b. One who is responsible for watching and guarding a performer during practice to prevent injury, as in gymnastics or weightlifting.
4. One employed by a dry cleaner to remove spots.