Lewis & Short

cŭbĭtum, i, n. (cŭbĭtus, i, m., Cels. 8, 1; 8, 16; Non. p. 201, 16) [id.], the elbow (serving for leaning upon).

  1. I. Prop., Cels. 1. 1.; Plin. 11, 45, 102, § 249; Plaut. Stich. 2, 1, 13; Verg. A. 4, 690; Ov. M. 7, 343; Hor. C. 1, 27, 8; id. S. 2, 4, 39; Quint. 11, 3, 93 al.
  2. II. Meton.
    1. A. The bending, curvature of a shore: orae, Plin. 3, 13, 18, § 111.
    2. B. As a measure of length, the distance from the elbow to the end of the middle finger, an ell, a cubit, Lucil. ap. Non. p. 201, 18; Plaut. Poen. 4, 2, 15; Cic. Leg. 2, 26, 66; id. Att. 13, 12, 3; Plin. 7, 2, 2, § 22; Suet. Aug. 43 al.
      Prov.: assiduo cursu cubitum nullum procedere, Cic. Att. 13, 12, 3; cf.: cursitare ac ne cubiti quidem mensuram progredi, Suet. Tib. 38.
      Hence, Ital. cubito; Fr. coude.