Is orthonym an official word and can it be found in any dictionaries?

"Orthonym" is not an official word and is not found in any standard dictionaries.

While it might sound plausible, it's likely a made-up term. It could be a misunderstanding of "orthography" or a neologism created for a specific context.

If you encountered this word, it's best to ask for clarification from the source where you found it.