A crush is when you like someone a lot (a strong feeling of attraction or infatuation). It’s usually a feeling of romantic interest that you have for someone who you may or may not know very well.
For example, if you have a crush on a classmate, you might feel nervous or excited around them, want to talk to them more, or feel happy when they pay attention to you. But having a crush doesn’t necessarily mean you’re in a relationship or that the other person feels the same way. It’s just a feeling you have.
Very Simple Definition:
A crush is when you really like someone.