Definition of "keynote" in English

noun

1. A speech that sets the main theme of a conference or other gathering; a keynote speech or keynote address.

2. The main theme of a speech, a written work, or a conference.

3. (music) The note on which a musical key is based; the tonic.

verb

1. (transitive) To deliver a speech that sets the main theme of a conference or other gathering.