Top definition
a person who is acting in an obnoxious manner, or is undesirable, this person really grinds your fucking gears.
Bob - "you see that girl ally last night? she was acting wild"

Jim - "yeah bro, she's a real fuckin mupbag"

Tom - "yo that kid Jeff jipped me on a dime bag"

Lisa - "yeah, he's a real mupbag like that"
by sb7733 January 17, 2017
Get the mug
Get a mupbag mug for your Facebook friend Jovana.