Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
nāvĭfrăgus, a, um, adj. [navis-frango], causing shipwrecks, dangerous (poet.): navifragum Scylaceum, Verg. A. 3, 553: fretum, Ov. M. 14, 6: saxa, Stat. Th. 5, 415; cf. naufragus, I. B.