nonchalant

The story

1. Old French · derived fromnonchaloir“to be unconcerned”
2. French · borrowed fromnonchalant
3. English todaynonchalant

Borrowed from French nonchalant, from Old French nonchaloir (“to be unconcerned”), from non- (“not”) + chaloir (“to have concern for”), from Latin non (“not”) + calēre (“to be warm”).