nước lã

Etymology
Perhaps from 🇰🇲, with lã deriving from. Compare.

Noun

 * 1) unboiled water

Usage notes

 * Strictly speaking, the fact that water is supposed to be boiled is for tea making, but for hygienic purposes, it has always been recommended that people shouldn't drink water straight out of a well or a tap; they should boil it first instead.