The condition that a woman is in when she has a decent personality and/or sense of humor, but is most definitely not sexually attractive to men.
Derived from a combo of "Shrek" and "sexy". Shrek was cool to hang out with, but uglier than 10 miles of dirt road.
Mike: Jason told me that his new girl Sally was real sexy.
Tom: No way man! I've seen her firsthand and that girl is Shrexy. He's just in denial.