The term “incel” was started in the late 1990s by a lovelorn Canadian woman who simply wanted to start an internet forum where she could discuss the issue with people like herself. Unfortunately, the term got appropriated by a subset of wretched young men who absolutely hate women because they will not put out for them. Occasionally, one of them will get violent and do something such as ramming a vehicle into a crowd of people.
So, if some SANE, REGULAR guy is not getting action, he probably shouldn’t call himself an incel and thus associate himself with these miserable wretches.
That group is mostly gone as an organized force when it was banned years ago. Incel is used far more as a term by feminists against their opponents these days.