This is the 4932nd most frequent Japanese word.
知らせ
Notice; information; notification.
知らせ is used to denote 'news' or 'a notification' in this sentence, referring to the information that has been received.
彼から重要な知らせが届いた。
I received important news from him.
知らせ here refers to specific information or news that has emotionally affected the subject.
その知らせは彼女をとても悲しませました。
That news made her very sad.
知らせ is used to mean 'notification' or 'message' in the sense of communication being sent.