Lewis & Short

1. căpĭtĭum, ĭi, n. [caput],

  1. I. a covering for the head: capitia = capitum tegmina, Varr. ap. Non. p. 542, 25; also an undervest, as put over the head, though Varr. derives it from capio: capitium ab eo quod capit pectus, id est, ut antiqui dicebant, comprehendit, Varr. L. L. 5, § 131 Müll.: induis, Laber. ap. Gell. 16, 7, 9 (Com. Rel. v. 61 Rib.); Dig. 34, 2, 24.
    A vestment of a priest, Hier. Ep. 64.
  2. II. The opening in the tunic through which the head passed (eccl. Lat.), Hier. Ep. 64; id. Vest. Sacerd. 14; Vulg. Exod. 28, 32; 39, 21; id. Job, 30, 18.