1. The parent of one's stepgrandparent.
2. The stepparent of one's grandparent.
My step-great-grandparent is a good person.
1- Step-great-grandparent's parent.
2- Great-grandparent's stepparent.
My step-great-great-grandparent is a good person.
1.) Your parents grandparents
2.) An awesome grandparent
Definition 1.
Mom: we are going to your great grandparents house for dinner today.
Kid: hell yeah! Grandma always makes cookies AND sneaks me a $20 bill!
Definition 2.
Grandpa: hey billy! Wanna go out for ice cream?
Billy: heck yeah! You’re such a great grandparent.