commissure

From Latin commissura (“a joining or connecting together”), from commissus (passive perfect participle of committo (“I join, I connect”)) +‎ -ura.

• (Received Pronunciation) IPA^(key): /ˈkɒm.ɪs.jʊə/
• (General American) IPA^(key): /ˈkɑm.əˌʃʊɹ/

commissure (plural commissures)

1. (anatomy) The joint between two bones.
   • 1734, William Stukeley, Of the Gout, J. Roberts, page 14:

     ...that round about the commissure of all our joints...

2. (neuroanatomy) A band of nerve tissue connecting the hemispheres of the brain, the two sides of the spinal cord, etc.
3. (anatomy) The line where the upper and lower lips or eyelids meet.
   • 1884, Elliott Coues, “§ 4.—An Introduction to the Anatomy of Birds.”, in Key to North American Birds. […], 2nd edition, Boston, Mass.: Estes and Lauriat, →OCLC, part II (General Ornithology), page 180:

     There is a third inner eyelid, highly developed and of beautiful mechanism: this is the nictitating membrane, or "winker" (nictito, I wink), a delicate, elastic, translucent, pearly-white fold of the conjunctiva. While the other lids move vertically and have a horizontal commissure, the winker sweeps horizontally or obliquely across the ball, from the side next the beak to the opposite.

• “commissure”, in Lexico, Dictionary.com; Oxford University Press, 2019–2022.
• “commissure”, in Merriam-Webster Online Dictionary, Springfield, Mass.: Merriam-Webster, 1996–present.

Learned borrowing from Latin commissūra.

• IPA^(key): /kɔ.mi.syʁ/

commissure f (plural commissures)

1. commissure

   la commissure des lèvres ― the corner of the mouth

• “commissure”, in Trésor de la langue française informatisé [Digitized Treasury of the French Language], 2012.

commissure f

1. plural of commissura

commissūre

1. vocative masculine singular of commissūrus