an act or instance of working or acting together for a common purpose or benefit; joint action.

more or less active assistance from a person, organization, etc.

We sought the cooperation of various civic leaders.

willingness to cooperate

to indicate cooperation.

Economics . the combination of persons for purposes of production, purchase, or distribution for their joint benefit

producers' cooperation; consumers' cooperation.

Sociology . activity shared for mutual benefit.

Ecology . mutually beneficial interaction among organisms living in a limited area.

noun

blockage , delay , encumbrance , handicap , hindrance , obstruction , prevention , stoppage

noun

aid , alliance , assistance , cahoots * , coaction , coadjuvancy , coalition , collaboration , combination , combined effort , communion , company , concert , concurrence , confederacy , confederation , confunction , conspiracy , doing business with , esprit de corps , federation , fusion , give-and-take , harmony , help , helpfulness , logrolling , participation , partisanship , partnership , playing ball , reciprocity , responsiveness , service , society , symbiosis , synergism , synergy , teaming , teamwork , unanimity , union , unitynotes:cooperation is always positive , collaboration is positive except in wartime (working with the enemy) , and collusion is always negative (working together in secret for a dishonest purpose) , affiliation , conjunction , connection , altruism , commensalism , kibbutz , lip service , mutualism , mutuality , parasitism , reciprocality