'post-humanist' originates from Latin, specifically the prefix 'post-' (from Latin 'post') meaning 'after', combined with 'humanist', which derives from Latin 'humanus' via Renaissance Latin/French forms related to 'humanism'.

'humanus' in Latin (meaning 'human') gave rise to terms like Renaissance Latin 'humanista' and Old French 'humaniste', producing the modern English 'humanist'. The modern compound 'post-humanist' was formed by attaching the Latin prefix 'post-' to 'humanist' to denote ideas 'after' or 'beyond' humanism.

Initially the elements meant 'after' (post-) and 'human'/'humanist' (concerned with human dignity and values); over time the compound has come to mean 'after or beyond humanism' and denotes either advocates of or perspectives aligned with posthumanist thought.