Here's how I came up with mine. I was building a Varnish-as-a-Service platform then. But I didn't want to use the word Varnish in my fqdn because it's a trademark. But also because the sum of its parts is more than Varnish (you've got scaling, security, etc).

So I focused on the essence of the thing I was building, which is caching. I couldn't find any concise domain with the word "caching" in it. So I played around with syllables and settled on Cachoid.com. I'm happy with the outcome so far https://www.cachoid.com/