water boy
/ˈwɔːtə bɔɪ/noun
1Usually with the and capital initial(s). The constellation Aquarius. rare before 20th cent.
2A boy who works beside a river or on a boat. Now rare.
3Chiefly US. A boy or man who carries or provides drinking water.
Origin
Mid 17th century; earliest use found in John Gower (fl. 1640). From water + boy.