look up any word, like cleveland steamer:
 
1.
Ball Sack; Scrotum; Male Genitalia
"Dude, your shorts are really tight, i can totally see your under luggage!"

"My under luggage is fragile, please handle w/ care!"

"Excuse me sir, its one carry one item per traveller, you're going to have to store your under luggage at the gate"
by Samsoniter March 18, 2010