take down a peg
take (one) down a peg (or two)
To reduce or damage someone's ego or pride; to humble or humiliate someone. I'm really glad that pompous oaf lost his court case, maybe that will take him down a peg or two. It's about time that someone took Sarah down a peg. Her snotty rich-kid arrogance is intolerable!
take someone down a peg (or two)and take someone down a notch (or two); knock someone down a peg (or two); knock someone down a notch (or two)
Fig. to reprimand someone who is acting too arrogant. The teacher's scolding took Bob down a notch or two. He was so rude that someone was bound to knock him down a peg or two.
take (someone) down a peg
To reduce the pride of; humble.