According to the chart used by courts and most genealogical societies, your brother's daughter's daughter would be your Grand Niece
Reference: http://freepages.genealogy.rootsweb.ancestry.com/~gentutor/chart.html
Your mother's mother's brother (your grandmother's brother) is your great uncle.
great uncle.
Your Uncle.
I call my mother mom
Your mother's mother is your grandmother.
He is your uncle, in most families he would be Uncle (Jack, Fred or what ever his first name is).
In Farsi, you would say "amoo" for mother's brother.
brother
You could call them as a brother/sister or as a cousin... If you're asking for yourself then good luck with that family.
His relationship to you is brother-in-law.
uncle
group of mothers
The word for uncle in Hindi is "ā¤ā¤žā¤ā¤ž" (chacha) for father's brother and "ā¤Žā¤žā¤Žā¤ž" (mama) for mother's brother.
Your mother's son is your brother or your half brother.