Lewis & Short

cellārĭus, a, um (access. form

  1. I. acc. plur. cellares, perh. for the purpose of avoiding the os four times repeated, Col. 8, 8, 1), adj. [cella], of or pertaining to a storeroom: sagina, Plaut. Mil. 3, 2, 31.
    Hence,
  2. II. Subst.: cellārĭus, ii, m., one who keeps provisions, a steward, butler, Plaut. Capt. 4, 2, 115; Col. 11, 1, 19; 12, 3, 9; 12, 4, 2; Plin. 19, 12, 62, § 188 al.