cooperates; cooperated; cooperating
1 : to work together : to work with another person or group to do something
It will be much easier if everyone cooperates.
Several organizations cooperated in the relief efforts.
The country agreed to cooperate with the other nations on the trade agreement.
2 a : to be helpful by doing what someone asks or tells you to do
The mother asked the child to put on his pajamas, but the child refused to cooperate.
Witnesses were willing/unwilling to cooperate.
— often + with
They said they would cooperate fully with the investigation.
He agreed/refused to cooperate with the police.
b : to act in a way that makes something possible or likely : to produce the right conditions for something to happen
We can barbecue on Sunday if the weather cooperates. [=if the weather is good enough]