Top definition
A person who wastes other people's time by pretending to be smart but is just a moron. If you see one of these people just say, you know where the door is and they will head on out if they know what's good for em.
Sometimes you just look and around and see all these mental infants fumbling around with whatever they are trying to do... sometimes it makes me cry
by Die_Tasse May 21, 2004
Get the mug
Get a Mental Infant mug for your father-in-law Callisto.