Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
† ecthlipsis, is, f., = ἔκθλιψις, gram. t. t., ecthlipsis, the elision of a final m with its vowel before an initial vowel, Diom. 2, p. 436; Charis. 4, p. 249.