'anaptyxis' originates from Greek, specifically the word 'anaptuxis', where 'ana-' meant 'up' or 'again' and 'ptysis' meant 'a folding'.

'anaptyxis' was borrowed directly from Greek into modern linguistic terminology, and its plural form 'anaptyxes' follows the Greek pluralization pattern.

Initially, it referred to the act of unfolding or expansion, but in linguistics, it evolved to mean the insertion of a vowel sound within a word.