Someone who only sleeps with other people's wives.
He is such a Segarra! She is married AND has a child!
a Meiler, but to a much farther, and grosser, extent
person 1: Dude, that chick's a Meiler.
person 2: Awesome.
person 3: Nah, she's a friggin segarra.
1 & 2: Eww, that's fuckin gross.