Lewis & Short

jānĭtor (‡ jānĭtos, Varr. L. L. 7, § 27 Müll.), ōris, m. [janua],

  1. I. a door-keeper, porter, janitor: heus ecquis hic est janitor? aperite, Plaut. Men. 4, 2, 110: carceris, Cic. Verr. 2, 5, 45, § 118: janitor (indignum!) durā religate catenā, Ov. Am. 1, 6, 1: utque sedens vester primi prope limina tecti, janitor egressus videt, id. F. 1, 138; Hor. S. 2, 7, 45; id. C. 3, 14, 23; Tib. 1, 1, 65; Col. 1 praef.
  2. II. Poet., transf.
    1. A. Caeli janitor, i. e. Janus, Ov. F. 1, 139.
    2. B. (Ingens) janitor, of Cerberus, Verg. A. 6, 400; cf. Hor. C. 3, 11, 16.