hot-water

The compound 'hot-water' is a straightforward combination of two ancient Germanic roots, forming a transparent descriptive term. 'Hot' originates from the Proto-Germanic haitaz, conveying the core concept of heat, while 'water' descends from the essential Proto-Indo-European noun wódr̥. Their union in English follows a simple and logical pattern of adjective-noun modification, directly describing heated water. This literal meaning later extended metaphorically to describe systems supplying heated water and, in the phrase 'in hot water', to a state of trouble or difficulty, though the compound itself retains its primary physical sense.

Structure: hot (temperature) + water (liquid) - hot: From Old English hāt ("hot, fervent, intense"), of Proto-Germanic origin. Functions as an adjective describing a high temperature. - water: From Old English wæter, from Proto-Germanic watōr, ultimately from Proto-Indo-European wódr̥. Functions as a noun denoting the clear liquid.