No, hearsay is when you try to given evidence about what someone else told you. It's not generally admissible, because the other side can't cross-examine the person who made the original statement.

In this case people gave evidence about what Carroll said at the time, and how it affected her. Two others gave evidence that Trump sexually assaulted them, which adds credence to Carroll's claims as there was a pattern of behaviour.

Trump's own testimony didn't help.