I think you may have a point -- what kind of user (A) has to deal with these roles, and (B) can't understand terms like 'DBA' or 'superuser'? Hopefully you're not just renaming roles already defined by the DBMS?

It sounds like you might not be dealing with non-technical business users here; if you can explain your users a bit better, you can probably get more help.

Otherwise...

If you can get spaces into the names, all to the good. Could just be too restrictive to use one-word role names. Longer names might look like: [database manager, table designer, table manager, writer, reader, banned]

Or use verbs: [administer, manage, design, write, read, do nothing.] This allow you to write friendly messages; "You may #{ role-verb } pages on this site."

If the database holds, say, web sites and pages, try to find actual career names; [database administrator, site manager, web designer, writer, customer, banned]

Hope that's some ideas.