'reformist' originates from English, formed from 'reform' + the suffix '-ist' (a suffix denoting an adherent or advocate). 'Reform' ultimately comes via Middle French and Late Latin.

'reformist' was formed in modern English by combining the noun/verb 'reform' (from Late Latin 'reformare' meaning 'to form again') with the agent-forming suffix '-ist' (from French/Latin '-ista'/'-iste'), producing 'reformist' to mean 'one who advocates reform'.

Initially, the root 'reform' meant 'to form again' (from Latin 'reformare'), and over time the compound word 'reformist' evolved to mean specifically 'an advocate of political or social change' rather than a literal re-forming.