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

The new Siri, along with other upgrades designed to bring more generative AI features to iPhones, Macs and other products, took center stage in Apple’s keynote address at its Worldwide Developers Conference in Silicon Valley.

From The Wall Street Journal • Jun. 8, 2026

A small group of protesters gathered outside early Monday morning ahead of the keynote to critique Apple's approach to child safety in its App Store.

From BBC • Jun. 8, 2026

But CEO Lip-Bu Tan provided a gentle reminder of the strength of demand for CPUs in his keynote speech at the Computex conference in Taiwan Tuesday.

From Barron's • Jun. 3, 2026

He said Huang’s endorsement of Marvell at a keynote speech in Taiwan sent a powerful signal to investors that the “transition to co-packaged optics is a near-term build, not a someday story.”

From MarketWatch • Jun. 2, 2026

Nonviolent and prayerful resistance to discrimination is the keynote.

From "Black Like Me" by John Howard Griffin