Uncle n. : 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.

Uncle n. : A pawnbroker.

Example:
An Uncle of mine has an addiction to crack cocaine. How can I help in this situation?

Taxonomy
Uncle, free encyclopedia, grandfather, relationship, reciprocal relationship, cousins, search, free dictionary, Latin, diminutive, avus, brother, elders, neighbors, acquaintances, strangers, Russia, Japan.

Defination from the web:
Uncle (Latin avunculus "little grandfather," diminutive of avus "grandfather,") is a family relationship or kinship, the brother or brother-in-law of a parent. ... grandparent · uncle · aunt · cousin · nephew · niece · common ancestor. family-in-law ...