Top definition
A phrase almost exclusively used by men talking about women.
A girlfriend with an absurdly high sex-drive, which initally seems great, but then you realise it's far higher than yours and you can barely keep-up, you can't sleep, you've no energy, you feel like death and STILL SHE WANTS MORE
James was overjoyed with his new girlfriend, but soon found-out that she was a fuckmonster.
by Andy WRX July 25, 2008
Happy St. Patties Day!
n. A girl who is always at the cock.
v. A person fucks like a fiend.
adj. Some who is too ugly to fuck
n. Damn Mo is such a fuck monster, she always grabing at my shit.

v. I tried to stay with it all night, but she was a fuck monster and I dried out.

adj. Look at Felix, he knows she aint looking at him, he's a fuck monster.
by P. Will November 04, 2006
Happy St. Patties Day!
A relationship definition somewhere between "friend-with-benefits" and "disease trader."
Ro Bag: "I'm not Katy's boyfriend, I'm just her Fuckmonster!"
by Marcus Chizzle December 06, 2005
Happy St. Patties Day!
One who frequently engages in carefree sportfucking without regard to commitment, reason, or partners' emotions.
Yulia: William is a dirty, dirty fuckmonster.
William: You know you love it.
by Dino February 10, 2005
Happy St. Patties Day!