colluder


col·lude

C0484700 (kə-lo͞od′)intr.v. col·lud·ed, col·lud·ing, col·ludes To act together, often in secret, to achieve an illegal or improper purpose: "The managers and the union leaders regularly colluded to rob the plantations at the expense of the workers" (Daniel Wilkinson).
[Latin collūdere : com-, com- + lūdere, to play; see leid- in Indo-European roots.]
col·lud′er n.