'antireforming' originates from a combination of the Greek prefix 'anti-' (from Greek 'anti') meaning 'against' and the English present‑participle 'reforming', which derives from Latin 'reformare', where 're-' meant 'again' and 'formare' meant 'to form'.

'antireforming' arose by compounding and has appeared in hyphenated or spaced forms such as 'anti‑reforming' or 'anti reforming', modeled on older compounds like 'anti‑reform' and eventually condensed into the single form 'antireforming' in modern usage.

Initially the elements meant simply 'against' + 'making/forming again'; over time the compound has come to mean more specifically 'against (the process of) reform' and is used adjectivally to describe opposition to change.