Is there a word or short term for words that have multiple valid spellings that don't correspond to any differences in meaning or pronunciation? The different spellings can be described as "spelling variants", but I'm looking for a word to describe the words themselves. I don't consider the term "homophones" (or the more specific "heterographic homophones") to be applicable because I understand it to refer to words that have different meanings.
A noun would be ideal ("Ax(e) is a(n) __") but an adjective that can modify a noun like word would be OK too ("Ax(e) is a(n) __ word"). To be clear, in this sentence I am using ax(e) to refer to the word itself, not to either of its two spelling variants. The word ax(e) is not a "variant" (n.): it comprises the two variant spellings <ax> and <axe>. I guess ax(e) could be described as a "variant word", using the adjective definition of variant that means something like "exhibiting variation", but I don't like this very much because it seems too ambiguous or unclear to me. However, if somebody can post an answer showing that "variant word" is some kind of established term for words like ax(e), I would be grateful for that information.
I'm not looking for the word variant
The questions Terminology for pairs of words with the same meaning, similar or same pronunciation but different spelling and Is there a word to describe words that can be spelled different ways? both look similar to mine, but neither has any answers that fit my sentence. I want to emphasize again that variant doesn't work for my purposes because I'm not looking for a word to describe the pair of spelling variants; I want a word to describe the single word corresponding to the multiple spelling variants.
If no such word exists, what is a good phrase for this?
I realize that such a word might not exist (as Pitarou's answer to the first linked question suggests); in that case, I'd be interested in hearing suggestions for a good multi-word term. The best I was able to come up with was "words with spelling variants not associated with different meanings or different pronunciations", which is pretty long.