'non-gas' originates from the prefix 'non-' meaning 'not' and the word 'gas', which comes from the Greek word 'khaos', meaning 'chaos'.

'Gas' was first used in the 17th century by the Flemish chemist Jan Baptist van Helmont, and 'non-gas' emerged as a term to describe substances not in a gaseous state.

Initially, 'non-gas' simply referred to any substance not in a gaseous state, and this meaning has remained consistent.