Lewis & Short

călĭgātus, a, um, adj. [caliga],

  1. I. wearing soldiers’ boots, booted: milites, Suet. Vit. 7 fin.; Dig. 3, 2, 2; 48, 3, 9; Inscr. Grut. 279, 3.
    Of a peasant in heavy shoes, brogans, Juv. 3, 322.
  2. II. Subst.: călĭgātus, i, m. (sc. miles), a common soldier, a private, = gregarius, Suet. Aug. 25; cf. Dig. 27, 1, 10.