barley water 
noun [mass noun] British
A drink made from water and a boiled barley mixture, usually flavoured with orange or lemon.He normally drinks barley water or fresh orange juice anyway....
- They must hate the way that the players drink orange barley water.
- Barley sugar is a sweet which was originally prepared from flavoured barley water made into a syrup with sugar and boiled to the verge of caramelization.