look up any word, like half chub:
 
1.
The flabby gelatinous skin-mass found on the underside of post menopausal women.
"Hey dawg, did you see the underguns on Angela Landsbury on last night's episode of Murder She Wrote."
by Kyle Wilkinson October 15, 2007
 
2.
underdog; underling.
I consider myself an undergun in the organization.
by uttam maharjan November 24, 2010