1. to become rough or less smooth in texture
2. to become less refined or more vulgar in manner or speech

Examples

• The fabric coarsens after repeated washing.
• His skin coarsens from years of outdoor work.
• The sandpaper coarsens the wood surface.
• Her language coarsens when she’s angry.
• Time coarsens the once-smooth stone.
• The material coarsens under extreme heat.
• His behavior coarsens around certain friends.