1. (n.) Combined action

2. (n.) the combined healthy action of every organ of a particular system; as, the digestive synergy.

3. (n.) An effect of the interaction of the actions of two agents such that the result of the combined action is greater than expected as a simple additive combination of the two agents acting separately. Also synergism.

accompaniment accordance agreement alliance association bipartisanship cahoots co-working coaction coadjuvancy coadministration coagency cochairmanship codirectorship coincidence collaboration collaborativeness collectivism collectivity collusion combination combined effort commensalism common effort common enterprise communalism communism communitarianism community complicity concert concerted action concomitance concord concordance concourse concurrence confluence conjunction consilience conspiracy cooperation cooperativeness correspondence duet duumvirate ecumenicalism ecumenicism ecumenism esprit esprit de corps fellow feeling fellowship harmony joining of forces joint effort joint operation junction mass action morale mutual assistance mutualism mutuality octet parasitism pooling pooling of resources pulling together quartet quintet reciprocity saprophytism septet sextet simultaneity solidarity symbiosis synchronism synergism team spirit teamwork trio triumvirate troika union united action