From Longman Dictionary of Contemporary Englishcop a pleacop a plea spoken informalAmerican EnglishSCADMIT to agree to say you are guilty of a crime in order to receive a less severe punishment Dunn copped a plea to avoid going to jail. → cop
Examples from the Corpus
cop a plea• Thought I was copping a plea on ... diminished responsibility.• Duckett copped a plea to avoid going to jail. 