let off

/L EH1 T AO1 F/
verb
  1. 1

    To cause to explode or come out; to release.

    โ€œStand back when you let off fireworks.โ€

  2. 2

    To forgive and not punish.

    โ€œThe boss let me off for breaking the office window, when in theory she could have fined me about 30 dollars.โ€

Source: https://en.wiktionary.org/wiki/let%20off