Best definition
winter cooter coat
when someone (usually a girl) allows over growth in the pubic area due to lack of razor or mate. And

in few cases a way it keep your under area warm in the winter.

“god Ashley did Ryan dump you? ‘cuz you’ve got one hell of a winter cooter coat going on. I can see it through your jeans…”

“its a good thing im single its cold so im thinking on saving money on razors and growing out my winter cooter coat