keynote
UK: ˈkiːnəʊt | US: ˈkiːnoʊt
n. the central theme or most important idea of a speech, event, or written work
n. (music) the note on which a key is based; tonic
vt. to deliver the main speech or set the central theme at an event
The word "keynote" originated in the mid-19th century, combining "key" (from Old English cǣg, meaning "essential" or "pivotal") and "note" (from Latin nota, meaning "mark" or "tone"). Initially used in music to denote the tonic or foundational note of a scale, it later expanded metaphorically to describe the central theme of speeches or events. The logic mirrors how a musical keynote anchors harmony, while a keynote speech anchors an event’s message.
The CEO delivered the keynote at the tech conference.
The professor’s lecture struck a keynote of environmental urgency.
In music theory, the keynote determines the scale’s tonality.
She was invited to keynote the annual leadership summit.
The documentary’s keynote was the resilience of human spirit.