'archaicist' originates from English 'archaic' + the suffix '-ist', where 'archaic' ultimately derives from Greek 'arkhaikos' (from 'arkhaios') meaning 'ancient' and '-ist' comes from Greek '-istes' via Latin/French meaning 'one who practices or is concerned with'.

'archaic' entered English via French and Latin from Greek 'arkhaios'; English formed 'archaicist' by adding the productive English suffix '-ist' to 'archaic', producing the noun meaning 'one concerned with archaic forms.'

Initially 'archaic' meant 'ancient' or 'old-fashioned'; 'archaicist' originally meant 'a person who studies or uses archaic forms' and has largely retained that sense while also being used for someone who prefers archaic style.