keynote

American  

[kee-noht] / ˈkiˌnoʊt /

noun

1. Music. the note or tone on which a key or system of tones is founded; the tonic.

2. the main idea or central principle of a speech, program, thought, action, etc.

3. the policy line to be followed, as by a party in a political campaign, that is set forth authoritatively in advance by an address or other formal announcement.

4. keynote address.

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verb (used with object)

keynoted, keynoting

1. to announce the policy of (a political party, campaign, assembly, etc.); deliver a keynote address at.

   The governor will keynote the convention.

2. to serve as the keynote for.

3. Music. to give the keynote of.

verb (used without object)

keynoted, keynoting

1. to provide a keynote, especially a keynote address.

   He refused an invitation to keynote.

keynote British  

/ ˈkiːˌnəʊt /

noun

1. 1. a central or determining principle in a speech, literary work, etc

   2. ( as modifier )

      a keynote speech

2. the note upon which a scale or key is based; tonic

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verb

1. to deliver a keynote address to (a political convention, etc)

2. to outline (political issues, policy, etc) in or as in a keynote address

Etymology

Origin of keynote

First recorded in 1755–65; key ¹ + note

Explanation

A keynote is "the leading note in a musical key," and that meaning has spread to include the leading theme or idea in almost anything. For example, a keynote speaker at a conference includes this central subject in her speech. You're most likely to find the word keynote followed by "speech," "address," or "speaker." The central keynote theme is often presented right at the beginning of a conference or seminar. Another meaning of keynote is "the leading note in a musical key." When you play a scale on the piano, the first, lowest, note is the keynote. This musical meaning dates from the mid-1700s, and the phrase "keynote address" was first used in 1905.

Example Sentences

That came a day after he delivered a keynote address at the company’s Worldwide Developers Conference in which Jobs introduced iCloud, the back end service that creates the seamless Apple experience.

From Barron's • Apr. 22, 2026

Dr Liz O'Riordan, who has had breast cancer three times, was a keynote speaker at the Let's Talk Women Health event held at The Hold in Ipswich on Saturday.

From BBC • Mar. 23, 2026

Something had shifted over those few days, a shift most eloquently expressed in Canadian Prime Minister Mark Carney’s keynote address.

From Salon • Mar. 19, 2026

With seven quarters to go until the end of 2027, revenue trends could get even better — something Huang also anticipated during his keynote.

From MarketWatch • Mar. 17, 2026

I accepted as many as I could fit into my school schedule, including keynote addresses at several large conferences for judges, social workers, and foster parents.

From "Three Little Words: A Memoir" by Ashley Rhodes-Courter