Have at it

have at (someone or something)

1. To strike or attack someone or something. The two boys had at each other until the teacher arrived to break up the fight.
2. To attempt or try to do something. Now that finals are over, I need to have at cleaning up my room.
3. To do something with energy and enthusiasm. It didn't take long for the kids to have at the cupcakes I'd set out. If you want to paint, have at it! All the supplies are still out.
See also: have
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.

Have at it.

Start doing it.; Start eating your food. John: Here's your hamburger. Have at it. Jane: Thanks. Where's the mustard? John: Did you notice? The driveway needs sweeping. Jane: Here's the broom. Have at it.
See also: have
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.
See also: