hap

The word "happy" comes from "hap" (happ). hap means luck, chance. So "mishap" and "happy" have a same etymology.

There are words from hap. mishap...unlucky incident hapless...unlucky haps...to happen coincidentally perhaps...by chance, based on hap

not so many （´ε｀

When I googled "etymology", found an interest thing! super clever.