A ewer is a jug or a pitcher — it’s a container used to hold and pour liquids. Ewers tend to be more decorative than useful.
The word ewer is a bit formal and even uncommon these days, but you may hear it used to describe ceremonial vessels like the ornate sterling silver America’s Cup, the trophy awarded to the winning yacht team in the America’s Cup race. It’s called a cup, but it’s really a ewer. The Latin root of ewer is aquarius, “of or for water.”