This article about women who’ve left the polygamous FLDS sect has an interesting clip, polyg, as a short form of polygamy with apparent adjectival usage. Here’s she’s talking about the rebellion she went through after her mother left polygamy behind:
“I think I was one of the first girls in the seventh grade to wear lipstick. I put henna in my hair to make it red. I wasn’t going to look like a little ‘polyg’ kid,” she said, using the slang “polyg” with all the contempt of a racial slur.
Clipping across the morpheme boundary – excellent! While examples aren’t exactly frequent (129,000 hits on Google, but that’s mostly hits for various chemical names) polyg does seem established as an adjective by those who use it. Some examples showed it being used as a noun, too, as in “where a lot of polygs went” and so on.
Another interesting use of this clipped form was here, where it’s short for polygraph.