1) (verb) Like sloppy seconds
or floppy fourths
but much dirtier... typically happens to the ugliest guy at a gang bang.
2) (noun) Typically a female who is willing to a partake in such an exercise will have a chach like a wizards sleeve as so many have been through her before, willing males are typically found drinking out the bottom of a keg, usually having found their beer goggles much earlier in the night and so not particularly aware that said female is the equivalent of the village bicycle.
1)That dude is fugly.. he's be damn LUCKY to get filthy fifths in a gang bang... with a one legged crack whore.
2) She is a filthy fiths slutbag.