|dīə|tänik, -nēk adjective
Etymology: Late Latin diatonicus, from Greek diatonikos, from diatonos stretching, extending (from diateinein to stretch out, extend, from dia- + teinein to stretch) + -ikos -ic — more at thin
1. of a Greek tetrachord : comprising two steps and a half step — distinguished from chromatic and enharmonic
2. : relating to a standard major or minor scale of eight tones to the octave without chromatic deviation
• di·a·ton·i·cal·ly -nə̇k(ə)lē, -nēk-, -li adverb