Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
Omphălē, ēs, f., = Ὀμφάλη, a queen of Lydia, whom Hercules served, Hyg. Fab. 32; Prop. 4, 10, 17; Ov. F. 2, 305; Stat. Th. 10, 646; cf. Preller’s Gr. Mythol. 2, p. 158.