A person with a jones for competition of any and all types.
My ex husband is the biggest playbaby I've even known.
1) Dating a girl who you have no real interest in; simply for the sex - no emotional attachment.
2) Planning on having sex with someone for a short duration of time.
Guy 1: Dude, the best way to get over your ex is finding some throw-away broad.
Guy 2: I already have one. Remember Shirley?
Guy 1: But you love Shirley.
Guy 2: Fuck off