uncle Meaning, Definition & Usage

  1. noun the brother of your father or mother; the husband of your aunt
  2. noun a source of help and advice and encouragement
    • he played uncle to lonely students

WordNet

Un"cle noun
Etymology
OE. uncle, OF. oncle, uncle, F. oncle, fr. L. avunculus a maternal uncle, dim. of avus a grandfather; akin to Lith. avynas uncle, Goth. aw grandmother, Icel. ai great grandfather.
Definitions
  1. The brother of one's father or mother; also applied to an aunt's husband; -- the correlative of aunt in sex, and of nephew and niece in relationship.
  2. A pawnbroker. Slang Thackeray.

Webster 1913