coars ‧ en /ˈkɔːs ə n $ ˈkɔːr-/ BrE AmE verb [intransitive and transitive]
1 . to become thicker or rougher, or to make something thicker or rougher:
Hard work had coarsened his hands.
2 . to become or to make someone become less polite in the way they talk or behave:
He’s been coarsened by his experience of war.