1) Any time a penis is particularly floppy, such as a few minutes after a good shag session.

2) A lazy person, especially someone who's always on the couch.

3) A pujorative term to describe someting that is floppy or more floppy than it should be.

1)Man, I just shagged Sarah hard for almost two hours, Ive got the worst flopcock Ive ever seen.

2)Ian wont even got off the couch to take a shit, what a flop-cock.

3)Man, those new springs I put in the truck are WAY better, especially after riding around on those old flop-cocks for three years.
by The Coondog October 20, 2006
Get the flopcock mug.
1. a small penis
2. more appropriately any guy named Bill's penis
Bill whipped out his flopcock on sarah.
by Mike March 31, 2005
Get the flopcock mug.