Lewis & Short

2. ostĭārĭus, a, um, adj. [ostium], of or belonging to the door: ancilla, portress, Vulg. Johan. 18, 17; usu. subst.

  1. I. ostĭā-rĭus, ii, m., a door-keeper, porter (syn.: janitor, portitor), Varr. R. R. 1, 13; Plin. 12, 14, 32, § 64; Vulg. 1 Par. 9, 22.
    By the rich they were, in early times, occasionally chained up, Suet. Rhet. 3.
    In the Christian church, a sexton, Cod. Th. 1, 3, 6; 16, 2, 27.
  2. II. ostĭāria, ae, f., a female doorkeeper, portress, Ambros. in Luc. 10, § 75; Vulg. 2 Reg. 4, 5; id. Johan. 18, 16.
  3. III. ostĭārĭum, ii, n., a tax upon doors, a door-tax: columnaria, ostiaria, frumentum, vecturae imperabantur, Caes. B. C. 3, 32 (called exactio ostiorum, Cic. Fam. 3, 8, 5).