canker sore

noun Pathology.

an ulceration of a mucous membrane, especially of the mouth.

Origin of canker sore

First recorded in 1905–10 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Medicine definitions for canker sore

canker sore


A small painful ulcer of the mucous membrane of the mouth; an aphtha.aphthous stomatitis recurrent aphthous ulcers ulcerative stomatitis
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.