tan·dem / ˈtandəm/ • n. (also tan·dem bicycle) a bicycle with seats and pedals for two riders, one behind the other. ∎ a carriage driven by two animals harnessed one in front of the other. ∎ a group of two people or machines working together. ∎ a truck with two rear drive axles.• adv. with two or more horses harnessed one behind another: I rode tandem to Paris. ∎ alongside each other; together.• adj. having two things arranged one in front of the other: satisfactory steering angles can be maintained with tandem trailers.PHRASES: in tandem alongside each other; together: a tight fiscal policy working in tandem with a tight foreign exchange policy. ∎ one behind another.