Definition of: enharmonic

(en′här·mon′ik) Music adjective
1. Having intervals less than a half-step.
2. Pertaining to that perfectly true intonation which is violated on keyed instruments to avoid complexity: C-sharp and D-flat are not the same in the enharmonic scale, though they are on the pianoforte.
3. Relating to that Greek scale whose intervals were quartertones and major thirds: distinguished from the diatonic and chromatic tetrachords.
—noun
1. An enharmonic chord or note.
2. plural Music distinguished by enharmonic intervals. [<L enharmonicus <Gk. enharmonikos <en- in + harmonia HARMONY]
—en′har·mon′i·cal adjective
—en′har·mon′i·cal·ly adverb