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"
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 18, 2017