granny
n. countable A2 Elementary US //ˈɡɹæni// UK //ɡɹˈæni// granny
n. a friendly and informal name for a grandmother. You use it when you are talking about your own grandmother or someone else's.
n. an informal or affectionate term for a grandmother. Often used as a term of address or as a familiar reference within a family context.
My granny always makes the best apple pie.
The children are spending the weekend at their granny's house while their parents are away on business.
Usage
Commonly used as a proper noun when addressing the person directly, in which case it is capitalised.