Lewis & Short

clāvĭcŭla, ae, f. dim. [clavis]

  1. * I. A small key, Caes. Germ. Arat. 195.
  2. II. A tendril, by which the vine clings to its props, Cic. Sen. 15, 52; id. N. D. 2, 47, 120; Col. 4, 6, 2; Plin. 23, prooem. § 5.
  3. III. A bar, bolt of the door, Hyg. Grom. 55.
    Hence, clāvĭcŭlārĭus, ĭi, m., a key-keeper, jailer, Firm. Math. 3, 66.