1. As nouns the difference between Anaptyxis and epenthesis is that Anaptyxis is (phonetics) epenthesis of a vowel – insertion of a vowel for example, the middle ‘(-a-)’ in (thataway), or use of infixes in coining english words on classical roots while epenthesis is (phoneticsprosody) the insertion of a phoneme, letter, or syllable into a word, usually