auntie

from WordNet (r) 3.0 (2006)

auntie
    n 1: the sister of your father or mother; the wife of your uncle
         [syn: {aunt}, {auntie}, {aunty}] [ant: {uncle}]

from The Collaborative International Dictionary of English v.0.48

Auntie \Aunt"ie\, Aunty \Aunt"y\, n.
   A familiar name for an aunt. In the southern United States a
   familiar term applied to aged negro women.
   [1913 Webster]