canker - Dictionary Definition : Vocabulary.com

A canker is something terrible that is hard to get rid of. Think of how you feel about the canker sore in your mouth. Drug use is a canker on our society, destroying lives and families.

In medicine, cankers are ulcers that are difficult to treat (the word is closely related to cancer). In agriculture, they are a disease that attacks the bark of apple trees. If one kid in your class misbehaves, and everyone suddenly follows his lead, that kid could be described (by your teachers) as a canker.

PRIMARY MEANINGS OF: canker

1	n v	an ulceration (especially of the lips or lining of the mouth) become infected with a canker
2	n	a pernicious and malign influence that is hard to get rid of

FULL DEFINITIONS OF: canker

1

n an ulceration (especially of the lips or lining of the mouth)

Synonyms:: canker sore

Type of:: ulcer, ulceration
a circumscribed inflammatory and often suppurating lesion on the skin or an internal mucous surface resulting in necrosis of tissue

n a fungal disease of woody plants that causes localized damage to the bark

Type of:: plant disease
a disease that affects plants

v become infected with a canker

Type of:: come down, sicken
get sick

v infect with a canker

Type of:: infect
communicate a disease to

2

n a pernicious and malign influence that is hard to get rid of

“according to him, I was the canker in their midst”

Synonyms:: pestilence

Type of:: influence
a cognitive factor that tends to have an effect on what you do