A speech intended to set out or summarize the central theme of conference, convention, etc., or to arouse enthusiasm for a party, cause, etc.; (more generally) the main or most prestigious speech at a conference or other event.
Origin
Late 19th century; earliest use found in Decatur (Illinois) Daily Republican.
Definition of keynote address in US English:
keynote address
noun
US
A speech intended to set out or summarize the central theme of conference, convention, etc., or to arouse enthusiasm for a party, cause, etc.; (more generally) the main or most prestigious speech at a conference or other event.
Origin
Late 19th century; earliest use found in Decatur (Illinois) Daily Republican.