"To reduce the sentence" means to decrease the length or severity of a punishment or prison term given to someone who has been found guilty of a crime. Full definition
If a federal bill reduces a sentence for a crime, can a prisoner get relief at the state level, possibly by stating the original sentence was cruel and unusual punishment? (law.stackexchange.com)
The judge reduced the sentencing to one count of animal torture. (animalfolksmn.org)
This did not reduce the sentence of those already imprisoned under the amended acts. (politics.stackexchange.com)