nincompoop Meaning, Definition & Usage

  1. noun a stupid foolish person
    poop; ninny.

WordNet

Nin"com*poop noun
Etymology
A corruption of non compos.
Definitions
  1. A fool; a silly or stupid person. Law
    An old ninnyhammer, a dotard, a nincompoop, is the best language she can afford me. Addison.

Webster 1913