Definition of "let down" [let down]

• To allow to descend (verb)
• To disappoint; to betray or fail somebody (verb)

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• "The master of Creative Confusion, of course, was the television character Columbo, who intentionally bumbled around until his suspect became so exasperated that he would let down his guard for the truly important question—the one pertaining to evidence of his guilt."
• "Then, somehow, I got my semihard penis in there, and I think my penis was so relieved to have made it inside that it let down its guard, spazzed out, and prematurely ejaculated."
• "Emotionally let down but not despairing, I examine the system, adjust the Prusiks, and consider whether I should shorten the anchor webbing again."