'prelatist' originates from the English noun 'prelate' combined with the suffix '-ist'. 'Prelate' ultimately comes from Latin 'praelatus' (past participle of 'praeferre'), where 'prae-' meant 'before' and the root relates to 'ferre' meaning 'to carry or bear'.

'prelatist' was formed in English from 'prelate' (which entered English via Old French 'prelat' from Latin 'praelatus'). The modern English formation added the agent-noun suffix '-ist' to indicate a person who advocates or supports prelacy.

Initially connected to the office or title 'prelate' (a high-ranking churchman), the term evolved to denote someone who supports the system or authority of prelates ('a supporter of prelacy').