Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
ungŭlus, i, m. [Oscan; Sanscr. ankami, bend; Gr. ἀγκύλος, crooked; Lat. ancus, aduncus; cf. angulus], a finger-ring, a ring (ante-class.): ungulus Oscorum linguā anulus, Fest. p. 375 Müll.; cf.: (anulum) apud nos prisci ungulum vocabant, Plin. 33, 1, 4, § 10; Poët. ap. Fest. l. l.; so Pac. ib. (Trag. Fragm. v. 64, 215 Rib.).