Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
ellipsis (en-l-), is, f., = ἔλλειψις, in rhet. lang., an ellipsis (pure Lat. detractio), Quint. 8, 6, 21; cf. id. 1, 5, 40; Schol. Juv. 1, 89.