canker sore n.
A small painful ulcer of the mucous membrane of the mouth; an aphtha. Also called aphthous stomatitis, recurrent aphthous ulcers, ulcerative stomatitis.
|an arrangement of five objects, as trees, in a square or rectangle, one at each corner and one in the middle.|
|a children's mummer's parade, as on the Fourth of July, with prizes for the best costumes.|