n. 1 comrade, confederate, collaborator, coadjutor; accessory, accomplice; associate, partner, friend I had hoped to have you as an ally in my proposal for reorganization The Allies finally defeated the Nazi war machine in 1945.
v. 2 league, combine, unite, join (up), team (up), side, band together, associate, affiliate, collaborate, confederate In their attempt at a take-over of our company, the raiders have allied themselves with two banks We shall ally the Romans to us and conquer the territory.