tandem
UK: ˈtændəm | US: ˈtændəm
n. 1. A bicycle with two seats and sets of pedals arranged one behind the other.
n. 2. A group of two people or things working together in close association.
adv. 3. One behind another; in tandem.
The word "tandem" originates from Latin, where it originally meant "at length" or "finally." It was humorously applied in 18th-century English to describe a carriage pulled by two horses harnessed one behind the other (rather than side by side), emphasizing the "lengthwise" arrangement. This later extended to bicycles and metaphorical partnerships. The modern sense of collaboration derives from the literal alignment of forces in sequence.
They rode a tandem bicycle along the beach.
The two departments worked in tandem to complete the project.
The policy was developed in tandem with community leaders.
The horses were hitched tandem for the parade.
Their skills complement each other perfectly when working in tandem.