to feel or express great sadness, especially because of someone's death

Queen Victoria mourned Prince Albert/Prince Albert's death for 40 years. 维多利亚女王为艾伯特亲王的去世服丧40年。

She was still mourning for her brother. 她还在悼念她的哥哥。

They mourned the passing of an older, simpler way of life (= felt sad because it had stopped existing). 他们为传统朴素生活方式的消亡而感到痛心。