'antitypy' originates from Greek, specifically the word 'antitupos', where 'anti-' meant 'against' and 'tupos' meant 'impression, model'.

'antitupos' changed into Late Latin 'antitypus', then into Middle English as 'antitype'; the Modern English form 'antitypy' arose by analogy or nominalization with the suffix '-y' to denote a state or instance.

Initially, it meant 'a counterpart or fulfillment of a prior type,' and over time it has retained that core sense though the word itself has become rare or archaic in usage.