(n) the insertion of a vowel or consonant into a word to make its pronunciation easier, Example:the insertion of a vowel in the plural of the word `bush' is epenthesis
The Collaborative International Dictionary of English (GCIDE) v.0.53 Collaborative International Dictionary (GCIDE)
‖n.; pl.Epentheses [ L., fr. Gr. &unr_;; 'epi` + &unr_; to put or set in. ] (Gram.) The insertion of a letter or a sound in the body of a word; as, the b in “nimble” from AS. nēmol. [ 1913 Webster ]