late 14c., curraunt, "that which runs or flows," from Old French corant (Modern French courant), from Old French corant (see current (adj.)). Meaning "a flowing," especially "portion of a large body of water or air moving in a certain direction," is from 1550s. Applied from 1747 to the flowing of electrical force through a conducting body (electricity formerly was regarded as a sort of fluid).
<a href="https://www.etymonline.com/word/up-current">Etymology of up-current by etymonline</a>
Harper, D. (n.d.). Etymology of up-current. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/up-current