coaction coadjuvancy coadministration coagency cochairmanship codirectorship collaboration collaborativeness collectivism collusion commensalism common effort common enterprise communalism communism communitarianism community complicity concert concord concordance concurrence cooperation cooperativeness duet duumvirate ecumenicalism ecumenicism ecumenism esprit esprit de corps fellow feeling fellowship harmony joining of forces joint effort joint operation mass action morale mutual assistance mutualism mutuality octet pooling pooling of resources pulling together quartet quintet reciprocity septet sextet solidarity symbiosis synergism synergy team spirit teamwork trio triumvirate troika united action