look up any word, like cleveland steamer:
 
1.
Your last pair of clean underwear, reminding you that this is your last chance to wear any unless you get your laundry done; that pair of ugly old underwear that you reserve for an emergency.
Dude, I gotta do laundry today, I've got my last chance undies on!
by breezy-licious July 17, 2011
 
2.
Old ripped underwear that you pack for a vacation trip then discard after wearing so you have less dirty laudry to pack for the trip home.
Julie: Why are you packing those ratty old briefs?
Augie: Think of them as disposable shorts, or last chance undies.
by Red Sam Black May 28, 2012