Definition

1. Noun:

   • A harmful and persistent negative influence: A corrupting element that spreads destructively within a system, group, or person's character.
   • An ulcer, especially in the mouth: A painful, often recurring sore or lesion, typically on the lips, gums, or inside the mouth.
   • A plant disease: A destructive fungal or bacterial disease of trees and woody plants that causes localized death of the bark, forming lesions or open sores.

2. Verb:

   • To infect with a canker: To cause to become diseased with a canker sore or a plant canker.
   • To become infected with a canker: To develop a canker sore or a plant disease.
   • To corrupt or destroy gradually: To have a slowly damaging and corrupting effect (archaic or figurative usage).

Usage Examples

• Noun (Harmful Influence):
  • Gossip is a canker that destroys trust within a community.
  • The historian described the corruption as a canker at the heart of the empire.
• Noun (Mouth Sore):
  • She couldn't eat spicy food because of a painful canker on her tongue.
• Noun (Plant Disease):
  • The apple tree was afflicted by canker, which killed several branches.
• Verb:
  • The infection cankered the rose stems. (To infect)
  • The peach tree cankered after the harsh winter. (To become infected)
  • Envy cankered his soul. (To corrupt - figurative/archaic)

Advanced Usage

• "to canker the rose": A classic literary metaphor for a hidden flaw or corruption that spoils something beautiful or perfect.
  • His bitterness was the secret that cankered the rose of their friendship.
• "cankerworm": (A related term) A caterpillar that is destructive to plants, often used metaphorically for a destructive force.
  • Debt was the cankerworm eating away at the family's finances.

Variants and Related Words

• Cankerous (adj): Having the nature of or resembling a canker; ulcerous or corrupting.
  • The cankerous growth on the tree trunk needed to be removed.
• Cankered (adj): Affected with or corrupted by canker.
  • The cankered branches were pruned to save the tree.

Synonyms

• Noun (Sore): Ulcer, sore, lesion.
• Noun (Influence): Blight, corruption, pestilence, cancer (figurative).
• Noun (Disease): Blight, rot.
• Verb: Corrupt, infect, blight, ulcerate.

Phrasal Verbs

(This word is not commonly used in phrasal verb constructions.)

Related Idioms

• A canker in the rose: A hidden fault or source of corruption that mars perfection.
  • Their public generosity was a canker in the rose, hiding their private greed.

Noun

1. a pernicious and malign influence that is hard to get rid of
   • racism is a pestilence at the heart of the nation
   • according to him, I was the canker in their midst
2. an ulceration (especially of the lips or lining of the mouth)
3. a fungal disease of woody plants that causes localized damage to the bark

Verb

1. infect with a canker
2. become infected with a canker