Money was named for its movement, from the Latin currere, to run.
The English word currency appeared in the 1650s, meaning the condition of flowing or running, from the Latin currentia, formed from currens, the present participle of currere, meaning to run.1 The same Latin root produced curriculum (a race course), courier (one who runs), and current (that which runs or flows).
The monetary sense, money in circulation, emerged by the 1720s. The word described not the money itself but its movement. Currency was what money did when it passed from hand to hand.2
Before standardized currency, exchange took many forms. Debt records on clay tablets preceded coins by thousands of years. The anthropologist David Graeber argued in Debt: The First 5,000 Years that the popular story of barter giving way to money had it backwards. Virtual credit systems came first. Physical coins came later, largely as a byproduct of military needs.3
The first known coins appeared in Lydia, in modern Turkey, around 600 BCE, made from electrum, a natural alloy of gold and silver.4
Paper money originated in China during the Tang dynasty (618-907 CE) as certificates of deposit issued by merchants. The Song dynasty formalized government-issued paper notes, called jiaozi, around 1024 CE.5 Europeans did not adopt paper money widely until centuries later.
The word's etymology preserves an observation that modern economics takes as a given. Money has value not because of what it is but because it moves. Currency named this insight six hundred years before economists formalized it into theory.6