Co-operate
CO-OPERATE, verb intransitive [Latin , to work.]
1. To act or operate jointly with another or others, to the same end; to work or labor with mutual efforts to promote the same object. It has with before the agent, and to before the end. Russia cooperated with Great Britain, Austria and Prussia, to reduce the power of Buonaparte.
2. To act together; to concur in producing the same effect. Natural and moral events cooperate in illustrating the wisdom of the Creator.