keynote

/ˌkiˈnoʊt/

/ˈkinəʊt/

Other forms: keynotes; keynoted; keynoting

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.

Definitions of keynote

1. noun

   (music) the first note of a diatonic scale
   synonyms: tonic

   types:

   C

   (music) the keynote of the scale of C major

   type of:

   musical note, note, tone

   a notation representing the pitch and duration of a musical sound
2. noun

   the principal theme in a speech or literary work
   type of:

   subject, theme, topic

   the subject matter of a conversation or discussion
3. noun

   a fundamental or central idea
   type of:

   idea, thought

   the content of cognition; the main thing you are thinking about
4. verb

   give the keynote address to (an audience)
   type of:

   address, speak

   give a speech to
5. verb

   set the keynote of
   “Comfort keynotes this designer's Fall collection”

   type of:

   set

   put into a certain state; cause to be in a certain state