I created the term "graphonyms" to denote words spelled the same, but perhaps with different meanings and different pronunciation. As noted in the file at this Wensite, "homonyms", the noun "lie" (synonymous with "prevaication") and the very "lie" (synonymous with "recline") are homonyms in being spelled the same and pronounced the same, but having different meanings. They are almost trivially two graphemes.

However, the two words "xxxxx" and "yyy" are nontically graphonymous", in being spelled the same, but pronounced differently.