To do something. Can also be used as an expression as anything: excitement, dismay, or disappointment. Typically used to describe an idiotic action by a peer. Can be used in conjunction with gee mumph. Famously coined in St. Louis by Stoner Steve B while he was high.
Stone Steve: Bet you chunk it.
Friend: DAMN IT! You fucked me up. I duffed it. I'm gonna take a mulligan.

Stoner Steve: you milly mumphed it.

Or

"Gee mumph! You milly mumphed it!"
by WalterWWhite July 31, 2021
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This is a great word. It is derived from the word Gee Mumph. It can mean anything. It is an explanation of someone screwing something up or something not going according to plan. It can also be used to haze others. Milly Mumph is something of a wonder. Originally coined by the awesome stoner Steve B from Missouri. Used by only the best.
Tommy: Mark, you really Milly Mumphed it this time.
Mark: Look at that guy, being a Milly Mumph.
Be careful or you'll Milly Mumph it again.
Stop being a Milly Mumph!
by Bill Lumberg August 4, 2021
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