1. in tandem - Adverb
2. in tandem - Phrase
one behind the other
Source: WordNetThe Internet feeds off the main press, and the main press feeds off the Internet. They're working in tandem. Matt Drudge
It has become evident that the primary lesson of the study of evolution is that all evolution is coevolution: every organism is evolving in tandem with the organisms around it. Kevin Kelly (editor)
Invented languages have often been created in tandem with entire invented universes, and most conlangers come to their craft by way of fantasy and science fiction. Joshua Foer
ride tandem on a bicycle built for two Source: Internet
riding horses down the path in tandem Source: Internet