a girl who attracts men like a cat is attracted to catnip. guys go crazy for this girl, for whatever reason. usually the man falls madly in love in the matter of days.
Kate: "DAMN MANNIP!"
Jessi: "You had another one fall hard for you, didn't you?"
Matthew: "I don't know what it is about Kate, but I am crazy about her."
Chris: "Watch out, bro, she's got mannip."