Yes, you can sell your domain name. Domain names are like real estate for web. There is a huge demand for good brandable custom domain names.
Trading domain names is a multi-million dollar industry. Since domain names are so cheap, smart entrepreneurs are always looking for great domain name ideas to get their hands own.
If you want to sell your domain name, then there are many marketplace websites like Sedo, GoDaddy, and others where you can list your domain for sale.