Casinos are a slippery material. I don't know how things are with online gambling in the USA but in Russia&Ukraine it's completely prohibited and websites are getting blocked country-wide. So guys running online casinos are registering a domain that is somewhat related to a casino's name like "Casino 777" or "Casino Vulcano", it gets blocked, they go and buy a lot of easy-memorable domains like "c777", "cas777", "cas-vul", "vulcano123" and use them as redirects.
The point is that it depends on laws in a country of however buys your domain. You can gain something by selling names with "casino" or you can try to offer your domains to the "not-that-good" type of guys I mentioned above. In any case, it's tricky & I won't bet much on this unless you're searching for a domain to run a casino of your own.