Her earnestness at work earned admiration from all her colleagues.

earnestness 是由形容词 earnest（认真的、诚挚的）加上名词后缀 -ness 构成的名词，表示"认真、诚挚的态度或品质"。后缀 -ness 通常用于将形容词转化为抽象名词，表示某种状态或性质。