notificationnoun [ C or U ]
uk/ˌnəʊ.tɪ.fɪˈkeɪ.ʃən/us/ˌnoʊ.t̬ə.fəˈkeɪ.ʃən/the act of telling someone officially about something, or a document that does this:
You must give the bank (a) written notification if you wish to close your account.
a message that is automatically sent to you to tell you there has been activity on one of your social media accounts, for example, when someone has commented on something you have written on Facebook™