Lewis & Short

commissūra, ae, f. [committo].

  1. I. Prop., a joining or connecting together; hence, in concr., a band, knot, joint, seam, juncture, commissure (class.): commissura funis, Cato, R. R. 135, 4; cf. nodorum, Sen. Ben. 5, 12, 2: molles digitorum, Cic. N. D. 2, 60, 150: mirabiles ossium, id. ib. 2, 55, 139; id. Univ. 7 fin.: navium, Plin. 16, 36, 64, § 158: nucum, id. 17, 10, 11, § 64: colorum, a mingling, id. 35, 5, 11, § 29; Sen. Q. N. 1, 3, 4: Piscium, the knot in the constellation Pisces, Plin. 18, 31, 74, § 311: vitis, Col. 3, 17, 4; id. Arb. 26, 9.
  2. II. In Quint. transf., connection in discourse, Quint. 12, 9, 17; cf. id. 7, 10, 16, 9, 4, 90: verborum, id. 9, 4, 37.