1 a junction, joint, or seam.
2 Anat. a the joint between two bones. b a band of nerve tissue connecting the hemispheres of the brain, the two sides of the spinal cord, etc. c the line where the upper and lower lips, or eyelids, meet.
3 Bot. any of several joints etc. between different parts of a plant.
Derivatives:
commissural adj.
Etymology: ME f. L commissura junction (as COMMIT)
Useful english dictionary. 2012.