- 1[intransitive, transitive] to become or make something become thicker and/or rougher Her hair gradually coarsened as she grew older. coarsen something His features had been coarsened by the weather.
- 2to become or make someone become less polite and often offensive in the way they behave [transitive, intransitive] coarsen (somebody) The six long years in prison had coarsened him.
NAmE//ˈkɔrsn//Verb Forms present simple I / you / we / they coarsen
he / she / it coarsens
past simple coarsened
-ing form coarsening