Noun. A word blend of undermine and maniac. Depicts someone who cannot help them self from making undermining comments. As with kleptomania the underminiac is largely unconscious of this behavior even though it might seem like they take sadistic gratification from it. Their victims are often left realizing how badly they were trashed for days and weeks afterward as many of the undermining comments are not initially obvious.

Invented in Borat's movie. It is said, when something great happens.