English Online Dictionary. What means uncle? What does uncle mean?
From Middle English uncle, borrowed from Anglo-Norman uncle, from Old French oncle, from Vulgar Latin *aunclum, from Latin avunculus (“mother’s brother”; literally, “little grandfather”; compare avus (“grandfather”)), from Proto-Indo-European *h₂euh₂-n-tlo (“little grandfather”), diminutive of *h₂éwh₂os (“grandfather, adult male relative other than one’s father”). Displaced native Middle English eam, eme (“maternal uncle”) (from Old English ēam (“maternal uncle”), containing the same Proto-Indo-European root, and Old English fædera (“paternal uncle”). Compare Saterland Frisian Unkel (“uncle”), Dutch nonkel (“uncle”), German Low German Unkel (“uncle”), German Onkel (“uncle”), Danish onkel (“uncle”). More at eam/eme.
- enPR: ŭngʹkəl, IPA(key): /ˈʌŋ.kəl/, IPA(key): [ˈʌn.kʰɫ̩], [ˈʌn.kɫ̩]
- Rhymes: -ʌŋkəl
uncle (plural uncles)
- The brother or brother-in-law of one’s parent.
- And it was while all were passionately intent upon the pleasing and snake-like progress of their uncle that a young girl in furs, ascending the stairs two at a time, peeped perfunctorily into the nursery as she passed the hallway—and halted amazed.
- (euphemistic) A companion to one's (usually unmarried) mother.
- (figuratively) A source of advice, encouragement, or help.
- (Britain, informal, dated) A pawnbroker.
- (Can we find and add a quotation of Thackeray to this entry?)
- (especially in the Southern US, parts of Britain and Asia) An affectionate term for a man of an older generation than oneself, especially a friend of one's parents, by means of fictive kin.
- (Southern US, slang, archaic) An older male African-American person.
- Ralph Waldo Emerson
- Plain old uncle as he [Socrates] was, with his great ears, — an immense talker.
- Ralph Waldo Emerson
- (dialectal, Scotland): eam, eme
- (with regard to gender): aunt
- (with regard to ancestry): niece, nephew
- (African-American): boy
- (India): aunty
- (brother of someone’s father): paternal uncle
- (brother of someone’s mother): maternal uncle
- (uncle gained by marriage): uncle-in-law
See also: related paternal uncle and maternal uncle for more translations.
- A cry used to indicate surrender.
uncle (third-person singular simple present uncles, present participle uncling, simple past and past participle uncled)
- (transitive, colloquial) To address somebody by the term uncle.
- (intransitive, colloquial) To act like, or as, an uncle.
- “uncle” in Douglas Harper, Online Etymology Dictionary, 2001–2019. 
- "uncle" in Merriam-Webster
uncle m (oblique plural uncles, nominative singular uncles, nominative plural uncle)
- (Anglo-Norman) Alternative form of oncle