Learn how to say Enharmonic correctly in English with this tutorial pronunciation video.
Oxford dictionary definition of the word enharmonic:
relating to or denoting notes which are the same in pitch (in modern tuning) though bearing different names (e.g. F sharp and G flat or B and C flat):
double flats and double sharps are replaced by their enharmonic equivalents in harp music
of or having intervals smaller than a semitone (e.g. between notes such as F sharp and G flat, in systems of tuning which distinguish them).
early 17th century (designating ancient Greek music based on a tetrachord divided into two quarter-tones and a major third): via late Latin from Greek enarmonikos, from en- ‘in’ + harmonia ‘harmony’