1. A line or place at which two things are joined.
a. A tract of nerve fibers passing from one side to the other of the spinal cord or brain.
b. The point or surface where two parts, such as the eyelids, lips, or cardiac valves, join or form a connection.
3. Botany The surface or place along which two structures, such as carpels, are joined.
[Middle English, from Latin commissūra, from commissus, past participle of committere, to join; see COMMIT.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2022 by HarperCollins Publishers. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.