The span of ribcage and collarbone displayed over a tank top or other low-cut shirt by a woman with very small breasts. Said woman may even dispense with wearing a bra on occasion.
“Dude, check out that clavage on the chick with the Browncoats cami. She’s pretty cute.”
“I don’t know, man, she’s kind of skinny.”
“Nah, man, I dig a gal with visible ribs.” (ed. I originally wrote something crasser here and then changed my mind… it’s my blog, I can write from my id if I want to…)
“I love that new sequined tank from Old Navy on you. It really shows off your clavage. You have such nice skin.”
“Thanks. I really love your new jeans. They really show off your ass(ets.) That cute girl over there is checking you out.”
She Curmudgeon: attempting to embrace her skinny minnie look in 2012, buy pants that fit, and displaying lots of clavage at a bookstore somewhere.