eyeballer

noun6

1. •
   A voyeur or inquisitive person.

   • 'Anyway, I'm no eyeballer, Miss Ruth.' — 1936
2. •
   One who estimates or judges based on visual inspection rather than detailed analysis.

   • Now a master eyeballer, I could accurately transpose almost any food into the equivalent value of another. — 2011
3. •
   An investigator who watches for signs of anything unusual or suspicious.

   • He must be a curbside eyeballer, a fence jumper, broad jumper, roof climber, cliff scaler, steeplejack and second story man. — 1973
4. •
   Someone who stares at another in order to intimidate them.

   • And any attempt to stare her down proved futile; she was a cow who simply could not be eyeballed without the eyeballer ending up burned out. — 2017
5. •
   Something eye-catching or worth noticing.

   • Maybe you noticed on the sport-show or the streets? No commercials. No ads. That's right. NO ADS. An eyeballer for you. — 1990
6. •
   A secret accomplice who surreptitiously watches the competition and interferes by causing a distraction to prevent the opponent from getting a good shot.

   • He would wear a phony diamond ring to flash in your eye, and he would have an “eyeballer” or kibitzer in the audience who would make a sudden noise or otherwise distract you while you were shooting. — 1965