noun a collection of fibers connecting parts of the brain or spinal marrow; a chiasma.
2. commissure ·noun the line of junction or cohering face of two carpels, as in the parsnip, caraway, ·etc.
3. commissure ·noun the point of union between two parts, as the angles of the lips or eyelids, the mandibles of a bird, ·etc.
4. commissure ·noun a joint, seam, or closure; the place where two bodies, or parts of a body, meet and unite; an interstice, cleft, or juncture.