From Middle Dutch siroop, from Old French sirop, from Medieval Latin siruppus, syrupus, from Arabic شَرَاب (šarāb, “a drink, beverage, wine, coffee, syrup”), from شَرِبَ (šariba, “to drink”). Related to sorbet, sherbet.
Compare French sirop, Italian siroppo, Spanish jarabe, jarope, Portuguese xarope.