Can I connect more than one domain to my site?

Yes. Use Add another domain on the Domain page. A site can have up to six addresses, where a domain plus its www counts as two.

One of them is your main address; visitors who use any of the others are sent to it, so you don't get duplicate sites in Google. Choose "Make … the main address" to switch which one leads.

To remove one, choose Disconnect this domain under it, then confirm. Your site stays live at its own address, and if that was the main address, your next connected domain takes over.