'oxygen-intolerant' originates from the combination of 'oxygen' and 'intolerant', where 'oxygen' refers to the chemical element essential for respiration, and 'intolerant' means unable to endure or accept.

'oxygen' comes from the French word 'oxygène', and 'intolerant' is derived from the Latin 'intolerans'.

Initially, 'intolerant' meant 'unable to endure', and this meaning has largely remained the same in modern usage.