E-pĕn' the-sĭs, n.

n.; pl. E-PĔN' THE-SĒS. [Gr. ἐπέν-θεσις, from ἐπεντιθέναι, to insert, from ἐπί and ἐντι-θέναι, to put or set in, from ἐν, in, and τιθέναι, to put or set; Fr. épenthèse.] (Gram.) The insertion of a letter or syllable in the middle of a word; as, alitum for altum.