: in the past : formerly cultures, erstwhile unknown to each other— Robert Plank. erstwhile. adjective. Definition of erstwhile (Entry 2 of 2) : former, previous erstwhile enemies.

How do you use the word erstwhile?

You use erstwhile to describe someone that used to be the type of person indicated, but no longer is. He ran away with an erstwhile friend of his wife's.

What is an erstwhile friend?

Erstwhile comes from Old English and is a formal way to say "former." You can go to your class reunion 20 years after you graduate high school and see your erstwhile friends. That means that they had been your friends, but you lost touch with them, so that they weren't friends of yours anymore.