A word girls use to describe usually well intentioned guys who haven't the slightest clue about how to interact with females without scaring the fuck out of them.
Guy: "So I wrote you this poem about how much I love you."
Girl: "Who the hell are you, anyway?"
Guy: "Oh, right. I'm Craig. I've been watching you with binoculars from the bushes for the last 2 months now"
Girl: "Whoah, that's kinda creepy. Get the fuck away from me."
Guy: "But I love you! Why can't you see that?!"
It's the male equivalent of a woman being called a "c*nt". Unfortuantely this is a word that has been co-opted by females to insult and punish men who they deem to be unattractive for "daring" to have the nerve to talk to them or approach them. Basically today's definition of "creepy" is anything an unattractive man says, thinks or does. For many women it's not enough to reject a guy - they need to punish him and humiliate him for being too short, too bald or too ugly by attacking his character like this.
An adjective used by young women to describe a man who they find actively unattractive.And/or an man who pays unwanted sexual attention to women and is clueless/oblivious to their lack of interest in him.