'epigenesist' originates from Greek, specifically the word 'epigenesis' (from Greek 'epigénesis'), where 'epi-' meant 'upon' or 'after' and 'genesis' meant 'origin' or 'birth', with the agentive suffix '-ist' (from Modern Latin/French) indicating 'one who advocates or practices'.

'epigenesist' formed in Modern English by adding the suffix '-ist' to the noun 'epigenesis' (a term used since early modern scientific writing) to denote an adherent of that theory.

Initially it referred specifically to a follower of the biological doctrine 'epigenesis'; over time the meaning has remained essentially the same, denoting someone who supports or advocates epigenesis in developmental or historical debates.