take down a notch

1. Also, take down a peg. Deflate or humble someone, as in He's so arrogant that I wish someone would take him down a notch, or That defeat took them down a peg. Both notch and peg in this idiom allude to a series, the former of indentations, the latter of knobs, used to raise or lower something. Specifically, peg alludes to the pegs used to lower a ship's colors. Their figurative use dates from the second half of the 1600s. Also see cut down, def. 4.

Example Sentences

For every actor or film Mr. Schickel praised, there seemed to be at least two he was happy to take down a notch.

From Washington Post