缺水 literally means 'lacking water' — 缺 (quē) means 'to lack' or 'to be short of', and 水 (shuǐ) means 'water'. Together, they form a compound noun meaning 'water shortage' or 'dehydration', depending on context. When referring to regions, infrastructure, or the environment, 缺水 describes insufficient water supply — for example, due to drought, poor management, or overuse. It’s commonly used in news reports, policy discussions, and environmental education.

In medical or daily life contexts, 缺水 often means 'dehydration' — a physiological condition where the body loses more water than it takes in, leading to symptoms like thirst, dizziness, or dry mouth. Unlike the English word 'drought', which applies only to prolonged natural dryness, 缺水 is broader: it can describe both systemic scarcity (e.g., in cities or farmland) and personal health conditions. It’s neutral in register and widely understood across formal and informal speech.