From Wiktionary, the free dictionary

From Middle English notifien, a borrowing from Old French notifier, notefiier.^[1]

• (General American) IPA^(key): /ˈnoʊtɪfaɪ/

notify (third-person singular simple present notifies, present participle notifying, simple past and past participle notified)

1. (transitive) To give (someone) notice (of some event). [from mid-15th c.]

   The dispatcher immediately notified the volunteer fire department of the emergency call.

   Once a decision has been reached and notified to the parties it becomes binding.

2. (obsolete, transitive) To make (something) known. [late 14c.] ^{[2] [3]}
3. (obsolete, transitive) To make note of (something).^[2]

As illustrated by the usage examples, the direct object of the verb can either be the party to which notice is given, or the event of which notice is given.

• apprise, inform; See also Thesaurus:inform

• notifier
• notification
• notifyee

• tonify