Answer: enharmonic

AnswerCrossword Clue
ENHARMONICRelative of chromatic.
enharmonicOf or having intervals smaller than a semitone (e.g., between notes such as F sharp and G flat, in systems of tuning that distinguish them)
enharmonicOf or relating to notes that are the same in pitch (in modern tuning) though bearing different names (e.g., F sharp and G flat or B and C flat)
enharmonicrelating to music constructed on a scale containing intervals of less than a semitone also ENHARMONICAL