commissure
(ˈkɒmɪsjʊə(r))
Also 5 comyssure, 6 commyssure.
[ad. L. commissūra putting together, joining, f. commiss- ppl. stem of committ-ĕre to put together: see commit and -ure. So F. commissure from 15th c.]
1. A joining or connecting together; the line or surface along which two parts touch each other or form a connexion; a joining, juncture, seam.
| c 1420 Pallad. on Husb. v. 42 His comyssure in erthe it stont so depe, And oute of it olyve ayein wol crepe. 1616 Surfl. & Markh. Country Farm 355 Any chinker, gaping, or rift, betwixt the commissures and joynts of the two barkes. 1624 Wotton Archit. in Reliq. (1672) 60 The sole Inconvenience of Shaking and Disjoynting the Commissures with so many strokes of the Chizel. 1677 Plot Oxfordsh. 101 Bent circularly to the hinge or commissure of the valves. 1727–51 Chambers Cycl., Commissure, in architecture, etc., denotes the joint of two stones. 1759 B. Martin Nat. Hist. Eng., Stafford II. 189 Their Striæ not being bent to the Commissure as those of all Oysters are. 1842 Blackw. Mag. LII. 159 The opposite halves..were placed in different hands, and a commissure effected by cementation. |
| fig. 1678 Cudworth Intell. Syst. i. iv. §36. 557 They made the Juncture and Commissure betwixt God and the Creature, so smooth and close, that where they indeed parted, was altogether undiscernible. |
2. A joint between two bones; formerly often applied to the seams of the cranial bones.
| 1541 R. Copland Guydon's Quest. Chirurg., Y⊇ commyssures or seames of the brayne panne or skull. 1607 Topsell Four-f. Beasts (1673) 109 There is no commissure or seam in his scull..but it is a continued bone. 1865 Grote Plato II. xxiii. 170 That my bones are held apart by Commissures. |
3. The line formed by the meeting surfaces of the two lips, eye-lids, etc.
| 1836 Todd Cycl. Anat. I. 306/2 There are three eye-lids [in Birds], two of which move vertically, and have a horizontal commissure. 1872 Darwin Emotions vii. 193 The commissure or line of junction of the two lips forms a curved line, with the concavity downwards. |
b. The connexion of the lips, eye-lids, etc. at the angles.
| 1755 Phil. Trans. XLIX. 191 A cancerous tumor..reached from the commissure of the lower lid..of the right eye. 1807–26 S. Cooper First Lines Surg. (ed. 5) 395 Dr. Cusack made an incision through the lower lip, beginning at its right commissure. 1859 J. Tomes Dental Surg. 399 The commissure of the lips being drawn back by the first and second finger. |
4. Various bands or bundles of white or grey nerve-substance, which connect the two hemispheres of the brain, different parts of the cerebrum and cerebellum, and the two sides of the spinal cord; also, a nerve-cord connecting two ganglia of the nerve system in insects, etc.
The various commissures of the brain and spinal cord are known as anterior, middle, posterior, white, grey, etc., according to their position and colour.
| 1809 Med. Jrnl. XXI. 159 What they say of the commissures of the brain and cerebellum. 1836 Penny Cycl. V. 332/2 The hemispheres of the cerebrum are united chiefly by a broad expansion of medullary matter..called the corpus callosum, or the great commissure of the brain. 1840 G. Ellis Anat. 21 The chiasma, or commissure of the optic nerves, is a squarish-shaped body. 1842 E. Wilson Anat. Vade-M. 366 The office of these commissures is the association in function of the two symmetrical portions. 1888 Rolleston & Jackson Anim. Life 120 The bands of nerve-fibres uniting the various ganglia are termed ‘commissures’ when they unite the ganglia of the same pair, e.g. the cerebral. |
b. A band of muscle, etc., connecting two parts of the animal body.
| 1870 Rolleston Anim. Life 31 Two long delicate bars of cartilage which are..anteriorly connected with each other by a fibrous commissure about the level of the angle of the lower jaw. |
5. Bot. a. The line of the cohering faces of two carpels; b. in mosses, the line of junction of two cells, or of the lid and mouth of the sporangium.
| 1830 Lindley Nat. Syst. Bot. 236 Bearing the seeds at the commissure along with the valves. 1863 Berkeley Brit. Mosses Gloss. 311. 1870 Hooker Stud. Flora 149 Umbelliferæ..carpels separated by a commissure. |