i) The visible portion of a woman's vulva, from behind, when she bends over.
ii) The amount the vulva protrudes (sticks out) downwards when a woman bends over.
iii) Cameltoe, as seen from behind, when a woman bends over.
Women who have a plump vulva with fleshy labia have a lot of underhang, while women with a flat vulva and lean labia have very little underhang. All the above definitions apply to both clothed or nude women.
a) Wow, check out the underhang on that gymnist!
b) A girl with a nice ass but little underhang is likecookies without milk.
Nickname given to bales of marijuana thrown overboard or out of airplanes. Origin is reportedly from members of the US Coast Guard in the area of Southern Florida.
"Base we've got some square groupers floating outside of Miami harbor."