the outermost part of a womans breast visible though the side of a tank top, specifically the under arm
"woah did you see the sleavage on that chick? I could almost see the whole boob"
by james prete January 04, 2008
The exposed side view of a breast thru loose fitting clothing like sideboob
Check it out, that girls tanktop is so loose you can totally see her sleavage!
by Dash8 December 25, 2005