Definition of "let down" in English

Verb

1. Used other than figuratively or idiomatically: see let,‎ down.

2. To allow to descend.

   • They let down the rope and I fastened it to the basket.

3. To disappoint; to betray or fail somebody.

   • I promised him I would meet him there, and I will not let him down.

4. To lengthen by undoing and resewing a hem.

5. To reduce one's level of effort.

6. To soften in tempering.

   • to let down tools or cutlery

7. To thin; to reduce the thickness or viscosity of.

   • let the sauce down with a little pasta water if it starts to become too thick; if the soup is too thick, you can let it down with a little milk; let the sauce down with a dash of the pickling liquor; use some of the stock to let down the onion sauce