The domain name doesn’t really do much for you in Google. I’m sure it helps out a tiny bit, but when it comes to natural ranking, it’s the links to your site that determine your position much more than your on-page factors. I don’t think you will see a difference either way you go.
For example, do a search for “online casino” (without the quotes) on Google and you will notice that not that many sites come up with the words “online casino” in their URL. I count only 2 in the top 10 results.
One thing you should probably avoid is having multiple dashes (-) in a domain. I know it isn’t in your example, but is a popular way to go these days and I’ve heard Matt Cutts (Google engineer) alude to their spammy nature. This is speculation, but it seems very easy for Google to write a simple line of code to hurt any site that has multiple dashes in it.