1. Ulceration of the mouth and lips.
2. An inflammation or infection of the ear and auditory canal, especially in dogs and cats.
3. A condition in horses similar to but more advanced than thrush.
a. A localized diseased or necrotic area on a plant part, especially on a trunk, branch, or twig of a woody plant, usually caused by fungi or bacteria.
b. Any of several diseases of plants characterized by the presence of such lesions.
5. A source of spreading corruption or decay.
v. can·kered, can·ker·ing, can·kers
1. To attack or infect with canker.
2. To infect with corruption or decay.
To become infected with or as if with canker.
[Middle English, from Old English cancer and from Old French cancre, both from Latin cancer, crab, malignant disease; see kar- in the Appendix of Indo-European roots.]
(click for a larger image)canker
canker on a rose stem
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. 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.