Refers to men having extremely hard, large and loud penises, seemingly immortal in their doing.
'So why are you called Whamo?'

'Close your eyes and hold out your hands'
by Brockodile Cumflea August 19, 2019
Whamo A word that you say to your friends after you nail a hot piece of ass.
Joe came out of the room and yelled "Whamo!" while a hot chick was getting dressed behind him.

Whamo!
by crue01 August 25, 2007
That "strength-test" attraction you see at carnivals where you hit a fulcrum with a mallet to ding a bell. Your success is based on your strength. Sometimes powered electronically.
"That dude seemed really confident, but he totally missed the ding on the whamo."
by UGotGlocked January 5, 2018