( BrE also co-operation ) / kəʊˌɒpəˈreɪʃn; NAmE koʊˌɑːp-/ noun [ U ]
1.
~ (with sb) (in doing sth) | ~ (between A and B) the fact of doing sth together or of working together towards a shared aim :
a report produced by the government in cooperation with the chemical industry
We would like to see closer cooperation between parents and schools.
2.
willingness to be helpful and do as you are asked :
We would be grateful for your cooperation in clearing the hall as quickly as possible.
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WORD ORIGIN
late Middle English : from Latin cooperatio(n-) , from the verb cooperari , from co- together + operari to work; later reinforced by French coopération .