Paragoge

II. Paragoge ·noun The addition of a letter or syllable to the end of a word, as withouten for without.

paragoge
părăgōgē, ēs, f., = παραγωγή, in gram., a lengthening of a word , the addition of a letter or sylla...

A New Latin Dictionary by Charlton T. Lewis Ph.D. and Charles Short, LL. D.