'postpredicative' originates from Latin-derived prefix 'post-' and the adjective 'predicative' (from Latin 'praedicativus'), where 'post-' meant 'after' and Latin 'praedicare' (root of 'predicative') meant 'to proclaim' or 'to declare'.

'postpredicative' was formed in modern English by combining the productive prefix 'post-' (from Latin) with 'predicative' (which entered English via Latin/Old French as 'praedicativus'/'predicatif'), producing a compound describing position relative to the predicate.

Initially, the parts meant 'after' (post-) and 'relating to proclaiming/declaring' (praedicare), but in grammar 'predicative' came to mean 'relating to the predicate'; 'postpredicative' therefore evolved to mean 'located after the predicate'.