enharmonic

Etymology

From Latin enharmonicus, from Late Latin enarmonius, from Ancient Greek ἐναρμόνιος (enarmónios), from ἐν (en)+ἁρμονία (harmonía).

adj

1. (music) Describing two or more identical or almost identical notes that are written differently when in different keys. (Whether they are identical depends on the tuning method used.)
   C sharp is enharmonic to D flat.
2. (music) Of or pertaining to a tetrachord.