canker sore vs canker

canker sore and canker both are nouns.

Word	Noun	Adjective	Verb	Adverb
canker sore	Yes	No	No	No
canker	Yes	No	Yes	No

As nouns, canker sore and canker are synonyms defined as:

canker sore and canker: an ulceration (especially of the lips or lining of the mouth)

canker sore (noun)	canker (noun)
an ulceration (especially of the lips or lining of the mouth)	a pernicious and malign influence that is hard to get rid of
	an ulceration (especially of the lips or lining of the mouth)
	a fungal disease of woody plants that causes localized damage to the bark

canker sore (verb)	canker (verb)
	infect with a canker
	become infected with a canker