Imagine you want to write a comment to an article you’ve just read. You want to refer to someone else who also posted a comment, so you type a phrase like “another commenter said …” and see that pesky red squiggly line under the word “commenter”. So you open a dictionary and type “commenter”… only to get a “Not Found” message, suggesting something like, “Did you mean ‘commentator’?”
Is there something wrong with the word commenter? Not at all. It is a common word in online forums, reddit, YouTube, and generally everywhere with a lot of comments, where it refers to anyone who posted a comment. Yet, the only word recognized by dictionaries and spell checkers is “commentator”. Does that mean that “commentator” is just a formal variant of “commenter”?
Sadly, it does not. A commentator is a person who provides commentary on a particular topic because it is their job or because they have some expertise in the field. A few examples from the media make that perfectly clear:
People posting comments under YouTube videos are not commentators. The person in the video could be called a commentator if he or she comments on specific topics and has a large audience.
So, what are you supposed to do if you do not want to use non-standard expressions but need to refer to a “commenter”? You can always use expressions like “the person who wrote the comment above”, but if you really feel that the word “commenter” would be more natural, my recommendation is to embrace it and ignore the squiggly line. I personally do not understand why it is not accepted by dictionaries, but I am quite certain it will find its way into major dictionaries eventually.