It’s also a Community.
Edit: You can also create a wikipost and ask your members for name suggestions, letting them add their suggested name(s) to the list. If they like a name already given, have them indicate that by adding a number after the name. Others can up the number if they also like it. By the end of a certain time period, you’ll have a list of possible names to go by.
I thought about a poll or vote, but you’d already need to have a list to start off with… and would have to add names afterward which could skew the results. Before we started our forum (made up of members of a now defunct forum), everyone suggested names (even multiple names). This enabled us not only to decide upon a domain name, but the forum name as well. This worked for us. 