by Rocket launcher man June 14, 2019

To pout, or be moody. Normally used in the Millheim, Pennsylvania area, and, sometimes, by Pennsylvania Dutch persons.
Neil is mupsing
by Studeguy54 June 27, 2017

Old US military slang for garbled audio in AM communications. Also adopted by civilian AM radio operators to describe the same phenomena. In common usage from 1940s to about 1980s.
by SUSFU February 12, 2021

You Mup
by Therealmupmaster November 27, 2019
