"aware of current events," 1762, French, "with the current, in the current (of events);" see au + current (n.).
Entries linking to au courant
Au
chemical symbol for the element gold, from Latin aurum "gold" (see aureate).
current n.
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).