cooperation (n.)

"the act of working together to one end," 1620s, from 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."