She calls them Aunt Casey and Uncle Toole.
Uncle Pumblechook rented his store from a person named Mr. Wopsle's great-aunt.
Uncle is to aunt as father is to mother.
Sister-in-law describes a female. Brother-in-law describes a male.
The opposite relationship of uncle would be Niece or Nephew.(The opposite gender is aunt.)
The son of your aunt and uncle is your first cousin.
If your aunt has a brother who is not your uncle, then your aunt is the wife of one of your parent's brothers, and that aunt's brother is no relation to you.
Great great aunt/uncle. To your niece, you are the aunt/uncle, to her child you would be the great aunt/uncle. So you would then be the great great aunt/uncle of her child's child (her grandson)
Your niece will call you her aunt or uncle.
In spanish, aunt is tia and uncle is tio.
I saw your aunt and uncle
Your uncle's sister is your aunt, or possibly your mother.
The Oz books penned by L. Frank Baum contain a character named Uncle Henry. Uncle Henry lived with Dorothy's Aunt Em on a farm in Kansas, United States.