Having attraction to multiple males -- sometimes several at once. Someone who is boy crazy will typically admit attraction to most males who enter their life at some point. The attraction is usually mutual but brief. The boy crazy person changes his/her mind about the boy(s); and the boy(s) that are subject to said "crazy," usually have either no interest in someone that is boy crazy, or has gotten what he's wanted and moves on. "Boy crazy" is often taken as an insult.
"Yergachef called me boy crazy and it's not true.
Their evidence was that I have one or more new love interest each week. That may be true, but it's not fair because my new love interests don't work out for any number of serious reasons. So I move on. That's hardly what I would call boy crazy. It's just that I missed out on dating as a teenager, and I have to make up for it." (Yes, she is boy crazy).
what you call a slutty girl when they're your friend.
peter: jenna is boy crazy.
neutral third party observer: no, jenna is a slut.
Overly concerned with having the reputation of being found attractive by boys. Distinct from slutty in that a girl who is boy crazy doesn't necessarily hook up with a lot of guys and might not be sexually active, but she incessantly talks about how cute boys are or that time that cute boy smiled at her and she can't decide which cute boy she likes. Can also be the sort of girl who always a boyfriend, less because she feels a special connection with any of her boyfriends and more because she feels incomplete without one.
"Wait, she's dating Sam now? I thought she was into Alex!"
"Yeah, she's just boy crazy."