'water-free' originates from English, specifically the words 'water' and 'free', where 'water' comes from Old English 'wæter' meaning 'water' and 'free' comes from Old English 'frēo' meaning 'not in bondage; free'.

'water-free' formed as a modern English compound from the Old English elements 'wæter' and 'frēo' (which became 'water' and 'free' in Middle/Modern English) and was used to describe something lacking water.

Initially it simply combined the senses of 'water' and 'free' to mean 'without water', and this basic meaning has been retained into modern usage.