Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
† trĭbrăchys, yos, m., = τρίβραχυς, a poetical foot consisting of three short syllables, a tribrach, Quint. 9, 4, 97.
Called also in Lat. tribrevis, Diom. p. 475 P.