Added 9 October 2026 semitone /ˈsɛmitoʊn/ noun Categories: LanguageRare Words noun ! Definition from Wiktionary (CC BY-SA). Pronunciation from Wiktionary, via Kaikki.org. More about semitone at Wordnik → Where our words come from → One of two parts, equal or unequal, in which a whole tone is divided. The semitone in 12-tone equal temperament, with frequency ratio of the twelfth root of two. The semitone in 12-tone equal temperament, with frequency ratio of the twelfth root of two. Any of the pitches of a chromatic scale. Related Words: diatonichalftonesubsemitonehalf-tonehemitonedemitonesemidiapasonsesquitone Back to today's word