coarsen

1. V-T/V-I If something coarsens or is coarsened, it becomes thicker or rougher in texture. 使变粗糙

Skin thickens, dries, and coarsens after sun exposure. 皮肤在阳光的暴晒下会变厚、变干且变粗糙。

...his gnarled, coarsened features. ...他那久经风霜、粗犷的线条。

2. V-T/V-I If someone's behaviour or speech coarsens or if they coarsen it, they become less polite or they begin to speak in a less pleasant way. 变粗俗

Her voice has deepened and coarsened with the years. 她的声音随着岁月变更越发深哑。

He had coarsened his voice to an approximation of Cockney. 他的声音变得跟粗俗的伦敦佬差不多。