A rare, genetic condition found in males, usually surfacing at the on-set of puberty; the result of which is a swift plummeting of the carrier's overall intelligence.
Young Abraham quickly went from smart as a monkey to dumb as a chimp, as a result of his dumbening.
(noun) Male or Female: A wannabe Dominant in the BDSM world, easily identified and laughed at by experienced lifestylers.
A Dumbinant will pretend to know everything. A Dumbinant never takes advice. A Dumbinant thinks that dressing in leather and carrying a flogger confers automatic dominant status toward anyone who identifies as a submissive.