Picking a domain name can sometimes be challenging. You want to pick something that is easy to remember and type and yet at the same time reflect what your web site is all about. If you are doing this in the context of building a search engine friendly site, it is all the more difficult.
Whois.net has an interesting tool here that might give you some ideas. You can search on a keyword or name, and it will display a list of retired domain names. I am not suggesting that you just pick from the list, but the results may inspire you.
Domains Bot does a more interesting job, by including synonyms of the word you search on. Again use the results as a guide to find what might suit you.
If you do happen to find a domain with these services that you are interested in, do a little research before you buy. You never know what might have been hosted at any random old domain in the past. Was it banned by Google? Did it host materials that you would rather not be associated with?
You can check in out the domain’s history using archive.org’s way back machine.