And then Lowell turned to the man he called the “cooperator”—Andrew Young.
“Investigators understood it as a way to order a hit on someone they believed was a cooperator,” said Barron.
She has been an efficient aid and cooperator with Frank in his gratuitous practice.
The librarian should always be treated as a cooperator, and not as an unintelligent servant.
also co-operate, c.1600, from Late Latin cooperatus, past participle of cooperari "to work together with" (see cooperation). Related: Cooperated; cooperating.