'dye-inert' is a modern English compound formed from the words 'dye' and 'inert', coined for scientific/technical use (20th century), where 'dye' meant 'a substance used to color materials' and 'inert' meant 'chemically or reactively inactive'.

'inert' originates from Latin 'iners' (in- 'not' + ars/ars- 'skill, activity'), passed into French as 'inerte' and then into English as 'inert'; 'dye' comes into English usage via Middle English forms (e.g. 'dey', 'deye') related to Old French terms for coloring, and both elements combined in modern English compounds such as 'dye-inert'.

The compound itself was coined with the clear modern technical meaning 'not affected by dyes'; the constituent 'inert' originally implied 'without skill or activity' in Latin but has come to mean 'inactive or unreactive' in chemical/physical contexts, which is the sense used in 'dye-inert'.