* Homonym is the actual word for a word that sounds the same as another word but has a different meaning (like "bear" the animal and "bear" the verb meaning to carry).
So, there isn't a real homonym for "homonym" in the traditional sense.
* However, you could argue that "homonym" itself is a homonym for "homophone" (words that sound the same but have different meanings and spellings).
It's all about how you define "homonym."