cut someone down to size

Images acquired from Wikimedia Commons and used with permission. Left image attribution: public domain. Middle image attribution: Horst Frank. Right image attribution: Tomas Castelazo.

Explanation:

If you look in front of most American homes you will see a lawn which is a large area of grass around the house or building. Americans are obsessed with keeping their lawns (the grass) short which is why we use the most powerful lawn mowers (grass cutters) in the world! When the grass grows over one centimeter, an alarm sounds inside of the home, and some guy runs out with a lawn mower and starts cutting it! He does this to keep his lawn at a particular length (a particular size). So, whenever the grass gets too long, he comes out with a lawn mower, and he cuts it down to size.

It's also possible to cut a person down to size, but in a way that is mental (in the mind) not physical. Some people are arrogant, and they believe that they are more important than other people. They think they're special, and everyone should admire them and kiss their feet! However, it's possible to cut them down to size (make them feel smaller) by showing them that they are not more important than other people.

Note: This expression is considered to be a form of negative communication in English.

When we cut someone down to size, we make that person understand that he or she is not more important than other people.

Example:

Sharon: Oh no! Here comes "macho" Marvin again, and he doesn't have his shirt on.

David: Unbelievable! What kind of person walks around an office with no shirt on. He doesn't even wear an undershirt!

Sharon: Well, he works out at a gym everyday, so he thinks that everybody should admire his muscles.

David: Yeah, you're right. Every morning he comes through here trying to put on a little show for the ladies. Then, he goes back to his office, and he sleeps for the rest of the day! You know, somebody should really cut him down to size!

Sharon: Well, I think we could do it. I've got an idea. Do you still have that can of blue paint in your desk?

David: Sure I do. But why?

Sharon: I was thinking that when Marvin falls asleep on his desk today, we can sneak in there and paint the word "macho" on his back. Then, the next time he walks around with no shirt on, everybody will laugh at him. He'll be so embarrassed that he'll run straight back to his office!

David: And that's where he will find the special present I'm going to leave for him.

Sharon: Oh yeah? What kind of present?

David: A large, thick shirt!

If you would like to learn to speak English clearly (like David and Sharon), you should check out the Speak English like an American course (aff).