Bedeutung von “let sb down” — Learner’s Dictionary

let sb down

phrasal verb with let us uk /let/ verb [ T ] present participle letting, past tense and past participle let

B2 to disappoint someone by not doing what you agreed to do:

I promised to go to the party with Jane and I can't let her down.

(Definition von “let sb down” aus dem Cambridge Learner's Dictionary © Cambridge University Press)