Fukushima Grandpa

An older person willing to sacrifice themselves to save younger people.

"That old dude that clacked off a vest at the Klan rally was a real Fukushima Grandpa!"

Uncle-grandpas

A term used to describe pyjamas only an old man would wear.

Did you see John last week? He ran across the street in his uncle-grandpas!

Uncle Grandpa

When your Step-Grandpa has an affair with your biological aunty, then marries her. Technically not insest, but still immoral.

He used to be my Grandpa by marriage (step) but had an affair with my aunty, so grandma kicked him out and he married aunty. He used to be grandpa, but now he is my uncle ... my uncle grandpa