cooperation (n.)

"the act of working together to one end," 1620s, from Middle French coopération, or directly from Late Latin cooperationem (nominative cooperatio) "a working together," noun of action from past participle stem of cooperari "to work together," from assimilated form of com "with, together" (see com-) + operari "to work," from PIE root *op- "to work, produce in abundance."