keynote - definition of keynote by the Free Online Dictionary, Thesaurus and Encyclopedia.
key·note (k n t) n. 1. The tonic of a musical key. 2. A prime underlying element or theme: "The keynote of the revolution settlement was personal freedom under the law" (G.M. Trevelyan). tr.v. key·not·ed, key·not·ing, key·notes 1. To give or set the keyno...