society > society and the community > social relations > association, fellowship, or companionship > [noun] > co-operation (3)
Combination in effecting any purpose or end, or in doing any work; co-operation of agents or causes.
Accordance in operation or opinion; co-operation; consent; = concurrence, n. 3 4.
Concurrence in action or causation, co-operation; combined action. Obsolete.