let up

verb

1. to diminish, slacken, or stop

2. informal,  (foll by on) to be less harsh (towards someone)

noun

1. informal,  a lessening or abatement

Idioms and Phrases

See let down , def. 2.

Cease, stop entirely, as in The rain has let up so we can go out . [Late 1700s]

let up on . Be or become more lenient with, take the pressure off, as in Why don't you let up on the child? [Late 1800s]