Noun: When a woman's legs possess so much fat and cellulite that it hangs over her knee. The resulting roll of fat is a gunk 'um.
Damn buh, have you seen how fat Brina got lately. She got gunk 'ums now and everything.
by BenZei December 04, 2005
The fat build up in between the thighs that rub (Also could be arm GUNK-UMS: The build up of fat on the side of the arm closest to the armpit)
I need to put vasaline between my legs because I get brush-burn on my GUNK-UMS!!!!
by word dropper November 11, 2009