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Cannon, Walter Bradford 1871-1945.
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American physiologist who did pioneering research on the autonomic nervous system, including the fight-or-flight response, and developed the concept of homeostasis.

The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2022 by HarperCollins Publishers. All rights reserved.
 
Can·non (kănən), Annie Jump 1863-1941.
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American astronomer noted for her work on classifying stellar spectra.
(click for a larger image)
Annie Jump Cannon
photographed c. 1922

The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2022 by HarperCollins Publishers. All rights reserved.
 
can·non (kănən)
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n. pl. cannonor can·nons
1. A weapon, typically mounted, that fires heavy projectiles from a cylindrical barrel. Cannons include guns, howitzers, and mortars.
2. The loop at the top of a bell by which it is hung.
3. A round bit for a horse.
4. Zoology The section of the lower leg in some hoofed mammals between the hock or knee and the fetlock, containing the cannon bone.
5. Chiefly British A carom made in billiards.
v. can·noned, can·non·ing, can·nons
v. tr.
1. To bombard with cannon.
2. Chiefly British To cause to carom in billiards.
v. intr.
1. To fire cannon.
2. Chiefly British To make a carom in billiards.

[Middle English canon, from Old French, from Old Italian cannone, augmentative of canna, tube, from Latin, reed; see CANE.]

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:

    Indo-European Roots

    Semitic Roots

    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.