TANDEM

I. noun Etymology: Latin, at last, at length (taken to mean “lengthwise”), from tam so; akin to Old English thæt that Date: circa 1785 1. a. a 2-seated carriage drawn by horses harnessed one before the other, a team so harnessed, ~ bicycle , a vehicle (as a motortruck) having close-coupled pairs of axles, a group of two or more arranged one behind the other or used or acting in conjunction, II. adverb Date: circa 1795 one after or behind another , III. adjective Date: 1815 consisting of things or having parts arranged one behind the other, working or occurring in conjunction with each other