The meaning of Anti-Christ is one who denies that Jesus is the Messiah. It's not just one person but all people who deny Jesus.

Christians, of course, believe that Jesus is Christ (which is Greek for Messiah). but also Muslims believe that Jesus is the Messiah too.

Who doesn't believe that Jesus is the Messiah?

Jews.
Atheists.
etc.

All of these people as a collective are the Anti-Christ.

https://youtu.be/NQmvb8RrFm8