1. Slang term, an idiot, nincompoop, lacking common sense. 2. An indolent person. 3. A cross between nincompoop and jackass.
by Hoyt of The Ledge May 26, 2006
Get the jack-a-ninnymug. Get the jack-a-ninnymug. Get the jack-a-ninnymug. Get the jack-a-ninnymug. We'll email you a link to sign in instantly.