A really ugly girl with too much self-confidence.
Look at Shareen in that ghetto dress, she's such a mumby.
by Competencies August 07, 2008
1 more definition
kid who got a cum slap on the face by another childs pillow.
if i were to jizz on my pillow then slap you in the face with it, mumby.
by shreshre naik November 15, 2006