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to lament; to grieve; to regret
to deplore
友人の突然の死を知って深く歎いた。
I grieved deeply upon learning of my friend's sudden death.
世の中の不公平さを歎くだけでは変わらない。
Simply lamenting the unfairness of the world will not change anything.
文化財の消失を歎く声が各方面から上がった。
Voices lamenting the loss of cultural assets were raised from all quarters.