US English - we do use "crush" as a verb, especially in the continuous forms ("Archie is crushing on Veronica." "He's really cute, I have been crushing on him for years.") But that's intermediate level slang. You don't want to try to use it until you're very comfortable with easy slang. :)

Just a reminder: "crush" is never used as a verb when we use the romantic meaning. We say "have a crush on someone" or we call someone "my crush".

It means a person you like romantically.

Your "crush" is the person you have a romantic interest in and want to get together with, but the two of you are not officially a couple yet.

My crush, means the person who I want to be my girlfriend or boyfriend. They are not your girlfriend or boyfriend yet and maybe they do not know you like them. But you have feelings for them.