Lewis Short
ungŭlus (noun 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.).
Charlton T. Lewis, Charles Short, A Latin Dictionary