User blog comment:Ikosarakt1/n-gons/@comment-39162-20140921205304

I think a nonagon should be called an enneagon to match with the greek(?) roots. A 2-angled polygon is called a digon if all the sides are straight, as well.

You can also get shapes named after the SI prefixes: the chiliagon (older and significantly more common form of kilogon) has 1000 angles, the megagon has 1 million angles, the gigagon has 1 billion angles, and so on.

There's also the apeirogon, which has infinity angles. Good for when you want to one-up someone in shape naming :)