Other forms: uncles
Your uncle is the brother of your mother or father. My uncle, Uncle James, a great-uncle.
It also covers the husband of your aunt, and in many families it is used for close family friends with no relation at all. Aunt is the counterpart. Great-uncle is your parent's uncle. Note Bob's your uncle, a British phrase meaning and there you are, whose origin is disputed; and Dutch uncle, meaning somebody who gives blunt advice for your own good.
1noununcleThe brother of your mother or father.
“His uncle taught him to drive on an airfield.”
uncle is a relative.
Latin avunculus means little grandfather and referred specifically to the mother's brother — from avus, a grandfather. Avuncular, meaning kindly in the manner of an uncle, keeps the Latin form intact.
Middle English
uncle
English, today
uncle
Built from
From Middle English uncle. From Middle English uncle, borrowed from Anglo-Norman uncle and Old French oncle, from Vulgar Latin aunclum, from Latin avunculus (“maternal uncle”) literally “little grandfather”, from Proto-Indo-European h₂euh₂-n-tlo- (“little grandfather”), a dialectal diminutive of h₂éwh₂os (“grandfather, adult male relative other than one’s father”) (whence also avus (“grandfather”)). Displaced native Middle English em (“uncle”) from Old English ēam (“maternal uncle”), containing the same Proto-Indo-European root, and Old English fædera (“paternal uncle”). Compare stq Unkel (“uncle”), Dutch nonkel (“uncle”), German Low German Unkel (“uncle”), German Onkel (“uncle”), Danish onkel (“uncle”). More at eam and eame.
Etymology from Wiktionary, CC BY-SA