If something coarsens or is coarsened, it becomes thicker or rougher in texture.
例句
Skin thickens, dries and coarsens after sun exposure.曬后皮膚會變厚、變干、變粗糙。...his gnarled, coarsened features.他那飽經風霜、粗糙的臉
V-ERG
(使)變粗俗;（使）變粗魯
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.
例句
Her voice has deepened and coarsened with the years...隨著歲月的流逝，她的聲音變得低沉粗魯起來。He had coarsened his voice to an approximation of Cockney.他讓自己的口音變得粗俗起來，接近倫敦東區的發音。