'oxy-gas' originates from the combination of 'oxygen' and 'gas', where 'oxygen' is derived from the Greek word 'oxys' meaning 'sharp' or 'acid', and 'gas' is derived from the Greek word 'khaos' meaning 'chaos'.

'oxy-gas' was coined in the early 20th century as a term to describe a mixture of oxygen and another gas used in industrial applications.

Initially, it referred to any mixture of oxygen and another gas, but over time it became specifically associated with welding and cutting applications.