accomplice
noun
°A cooperator.
"Success unto our valiant general, And happiness to his accomplices! - Shakespeare, Henry VI Part I, V-ii"
°An associate in the commission of a crime; a participator in an offense, whether a principal or an accessory.
"And thou, the cursed accomplice of his treason. - Johnson"
synonyms: abettor, accessory, assistant, confederate more» , coadjutor, promoter