Learner's definition of PROSECUTION
1 : the act or process of holding a trial against a person who is accused of a crime to see if that person is guilty
2 the prosecution : the side of a legal case which argues that a person who is accused of a crime is guilty : the lawyer or lawyers who prosecute someone in a court case
— often used before another noun
The prosecution called their first witness.
The prosecution rests, Your Honor.
The defense told the jury that the prosecution had not proved its case.
3 [noncount], formal : the act of doing or continuing to do something — usually + of