Definition:
Gotchies are underwear (underpants, specifically). Also referred to as "under gotchies."
Usage:
My Mom would often yell at us kids in the mornings, "Come on, let's get ready to go! Go put your undergotchies on!"
Explanation:
No explanation for this term. But, we used it exclusively as the term for underwear when I was growing up (1970's).
