(n) refers to females who -.because something belongs to them, or they created something (a baby) - cannot step back and see that it is hideous-looking and repulsive to most everyone else (and especially men) who look at the same thing.
Named after the medically known fact that the majority of women who birth ugly babies believe that this said baby is absolutley beautiful.
Do you see Tanisha's new baby?
"Yes. Man, is that think butt-ugly or what? And she keeps going on and on and on about how it's the most beautiful baby that she's ever seen."
She's got Ugly-Baby-Syndrome, for sure! She does the same thing with her hideous-looking shoes too -- she's always wearging some ugly heels and she thinks they're beautiful.