noun. In phonetics, the involuntary utterance of an auxiliary vowel, especially before r, l, m, and n, in certain positions, as in lucre, able, chasm, etc.

noun. epenthesis of a vowel – insertion of a vowel. For example, the middle ‘-a-’ in thataway, or use of infixes -i- and -o- in coining English words on classical roots.

"I might also be interested to find out that vowel insertion is widespread enough in the world's languages to have a name, epenthesis also called anaptyxis."

excrescence  

interconsonantal  paragoge  tmesis  

epenthesis  

linking vowel