A term used by a male to inform another male that there is a female in eyeshot sporting visible THO. That male is then expected to discreetly survey the area, locate the female and inspect her nipple(s). Often accompanied by a nudge and or a widely open-eyed head gesture toward the female.
I was frothing pure horndog at the gym while a hottie was squatting a whole pound so I snipered a picture of her butt/box gap while she wasn't looking and put it on the internet.