Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
segmen, ĭnis, n. [seco], what is cut off, a cutting, shred, little bit (very rare): unguium et capilli segmina, Fab. Pictor ap. Gell. 10, 15, 15: nulli secabile segmen, i. e. atom, Aus. Ecl. 1, 7: cannarum duplex fixa perpetuitas nec segmina, nec rimam ullam fieri patietur, i. e. will prevent the work from chipping off or cracking, Vitr. 7, 3.