'Black belt' definitions:

Definition of 'black belt'

From: WordNet
noun
A person who attained the rank of expert in the martial arts (judo or karate)
noun
A black sash worn to show expert standards in the martial arts (judo or karate)

Definition of 'Black belt'

From: GCIDE
  • Black belt \Black" belt`\ (bl[a^]k"b[e^]lt`), n. (Martial arts) a comedy that treats of morbid, tragic, gloomy, or grotesque situations as a major element of the plot. [PJC]

Synonyms of 'black belt'

From: Moby Thesaurus