To abandon somebody, leaving him or her holding the responsibility or blame.
To remove the value from an article or arrangement and leave somebody holding the empty (or valueless) container.
To disappoint; to betray or fail somebody
To reduce one's level of effort.
To soften in tempering.
Used other than figuratively or idiomatically: see let, down.
To allow to descend.
To lengthen by undoing and resewing a hem.