A woman who is so stick thin that her head looks too big for her body. Very popular among celebrities these days.
"That actress would be much prettier if she wasn't such a ladypop."
This is a more "mixed company" friendly way to express the above expletive. This can be used as an adjective but it's more commonly just used as an angry outburst.
"That MFCS just rear-ended my new car!!"
Joe - "Hey, Tom, I just saw Pete with his tongue down Kelly's throat. Isn't she supposed to be YOUR girlfriend?"
Tom - "MFCS!!!!!"