One who has tank butt. A huge round, full, healthy wide ass. An ass that can, if unleashed cause mass destruction and histeria amongst those of the opposite sex. Lithe baby blue sweat pants cling lovingly to Tank Butts. Jean pants strain to hold the strong defined curves, which define Tank Butt.
"Shut up Tank Butt!" in reference to a women, most likely Melissa, who has a well defined Tank Butt. Melissa indeed has the Poster Butt for Tank Butthood.