Let-off refers to a situation where someone is forgiven or not punished for something they have done wrong. The antonyms for let-off, therefore, are those words that describe a situation where punishment is given or not forgiven. These words include discipline, penalty, retribution, punishment or consequence. For instance, when a child misbehaves and doesn't receive a let-off from their parents, they may be disciplined or given a consequence to teach them a lesson. Similarly, in the legal system, someone who is found guilty of a crime may receive a penalty or punishment for their actions, instead of a let-off. In summary, antonyms for let-off describe situations where consequences are given instead of forgiveness.