Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
călĭga, ae, f. [cf. calceus, from calx], a shoe of leather, esp. that worn by the Roman soldiers (cf. Dio, 48, 12; Smith, Antiq., and Becker, Gall. III. p. 134, 2d ed.), a half-boot, a soldier’s boot.