To make someone leave their job because they are too old. Also, to be too old to work anymore.
This word can make people think of retirement, getting older, or not being useful anymore.
Examples:
The company will superannuate him next year.
He superannuated last month and now he stays home.
She is superannuated and doesn't work anymore.
The dog is superannuated and doesn't chase cats anymore.
The superhero was superannuated and had to retire from saving the city.
My grandpa was superannuated and now he just fishes all day.