Slang term meaning a Grandmother in her 60s or older who is so cool and up to date that she has an Instagram. She is referred to as insta grammeth.
I went to visit my awesome, very young at heart grandmother who is very modernized, and greeted her by saying "Hi!, How are you insta grammeth ?"
by Dict pseucker August 10, 2017
buy the domain for your pet vlog