In tandem with the CIA, MI6 were in the midst of running their most successful espionage operation to date.
Of course, techniques for money laundering and fraud have gotten more sophisticated in tandem.
The brain, composed of all kinds of decentralized circuits that work in tandem, has no central command center.
1785, "carriage pulled by horses harnessed one behind the other," punning use of Latin tandem "at length (of time)," from tam "so" + demonstrative suffix -dem. Transferred by 1884 to bicycles with two seats.