To make or become rough or harsh in texture or quality. The constant exposure to the sun and wind began to coarsen the fabric of the outdoor furniture.
To make or become less refined or cultured. The comedian's humor began to coarsen over the years, appealing to a broader but less sophisticated audience.
In materials science, to cause grains or particles within a material to grow larger and fewer, typically during heat treatment. During prolonged annealing, the alloy's precipitates coarsen, reducing its overall strength.