This is a word used in reference to the female mind. Usually used by an ignorant male when he doesn't take the time to understand a female's point of view or doesn't want to take responsibility for his own actions, he'll use this term to make himself look/feel better to his homies.
Male 1: "Dude, your girl is really pissed. Why didn't you call her & tell her you were cancelling so she could have gone & done something else?"
Male 2: "Girls have headworms and there is no cure."