In Italian, "Clessidra" typically means hourglass. However, the word has its roots in ancient Greek, from κλεψύδρα (klepsudra), meaning water-clock. The Greeks used water-clocks to measure time as water flowed—or was "stolen"—from one container to the next. In Greek, "kleps" is akin to our word "klepto" (to steal), and "udra" is related to "hydro" (water).