Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
Sĕgĕtĭa, ae, f. [seges], a goddess that protects the standing crops, Macr. S. 1, 16; Aug. Civ. Dei, 4, 8; called also Sĕgesta, Plin. 18, 2, 2, § 8; cf. Becker, Antiq. vol. 4, p. 15.