n.--A pair of underwear worn after someone else has already "soiled" them.
v.--Wearing a pair of underwear that has previously been worn by someone else without washing in between
Darren: Hey, bro. I'm all out of clean undies.
Mikael: It's all good, dude. Take mine.
Darren: I don't want your soiled seconds.
Pookie sticks head in
: Well, I'll wear 'em...