I prefer the word roughness to the word irregularity because irregularity -- to someone who had Latin in my long-past youth -- means the contrary of regularity.
我喜欢“粗糙”这个词 而不是“不规则” 因为“不规则”—— 对于象我这样 年轻时学过拉丁文的人来讲—— 是“规则”的反义词