light water
noun
mass noun
1
- water containing the normal proportion (or less) of deuterium oxide, i.e. about 0.02 per cent, especially to distinguish it from heavy water轻水（即通常的普通水）。
2
- foam formed by water and a fluorocarbon surfactant, which floats on flammable liquids lighter than water and is used in firefighting轻水泡沫灭火剂。