'posthuman' originates from Latin and Latin/Old French roots, specifically the prefix 'post-' (from Latin 'post') and 'human' (from Latin 'humanus'), where 'post-' meant 'after' and 'humanus' meant 'of or belonging to man'.

'posthuman' developed in modern English in the late 20th century as a compound (often written 'post-human' early on) in fields like philosophy, cultural theory, and science fiction to describe states or beings 'after' or 'beyond' the human; it eventually stabilized as the single-word form 'posthuman' in contemporary usage.

Initially the components simply meant 'after' + 'human' (i.e., following humans in time or sequence), but over time the term evolved to mean beings, states, or perspectives that transcend or fundamentally alter what is considered 'human' today.