let someone down

1

Fail to support someone; also, disappoint someone. For example, I was counting on John to come, but he let me down, or The team didn't want to let down the coach. [Late 1400s] A British phrase with the same meaning is let the side down, alluding to some kind of competition (sports, politics) and dating from the mid-1900s. It is occasionally used in America.

2

let someone down easy. Convey bad or disappointing news in a considerate way, so as to spare the person's self-respect. For example, The teacher knew that Paul would have to repeat the course and that there was no way to let him down easy. [Colloquial; mid-1700s] Also see let down.

Words nearby let someone down

let ride, let sleeping dogs lie, let slide, let slip, let someone, let someone down, let someone have it, let the cat out of the bag, let the chips fall where they may, let the grass grow under one's feet, let the side down