1. (使)變粗糙 If something coarsens or is coarsened, it becomes thicker or rougher in texture.
e.g. Skin thickens, dries and coarsens after sun exposure. 曬后皮膚會(huì )變厚、變干、變粗糙。 e.g. ...his gnarled, coarsened features. 他那飽經(jīng)風(fēng)霜、粗糙的臉
2. (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.
e.g. Her voice has deepened and coarsened with the years... 隨著(zhù)歲月的流逝，她的聲音變得低沉粗魯起來(lái)。 e.g. He had coarsened his voice to an approximation of Cockney. 他讓自己的口音變得粗俗起來(lái)，接近倫敦東區的發(fā)音。