What does the phrase have at It mean?

The phrase "have at it" is an informal expression meaning to start or begin something, often with determination or enthusiasm. It can also imply a challenge or a willingness to engage in a task or confrontation.

Here are some examples of how "have at it" can be used:

* "I'm ready to tackle this project. Have at it!"

* "The two teams were ready to have at it in the championship game."

* "If you're going to try to climb that mountain, you'd better have at it with all your might."

It's similar to saying "go for it," "get started," or "let's do this."