I have two questions here.
1. What does 'com' mean in the name of a website, for example, www.wordreference.com?
2. How to pronounce 'com' in the name of a website, /kɒm/ or /kʌm/?
Note that while ".com" might have been initially intended to designate commercial websites, as opposed to educational (.edu), government (.gov), military (.mil), etc., in practice it has become a more generic, almost meaningless term - there isn't much in the way of commerce happening at wordreference.com, for example - similarly, anyone can register a .org (originally intended to designate a "non-profit") site.