canker

1 of 2

noun

can·​ker ˈkaŋ-kər 

1

a(1)

: an erosive or spreading sore

(2)

: an area of necrosis in a plant

also : a plant disease characterized by cankers

Citrus canker is caused by bacteria.

b

: any of various disorders of animals marked by chronic inflammatory changes

2

archaic : a caterpillar destructive to plants

3

chiefly dialectal : rust sense 1

4

: a source of corruption or debasement

suspicion is a canker that … will consume and waste all love

—R. Sibbes

5

chiefly dialectal : dog rose

cankerous

ˈkaŋ-k(ə-)rəs 

adjective

canker

2 of 2

verb

cankered; cankering ˈkaŋ-k(ə-)riŋ 

transitive verb

1

obsolete : to infect with a spreading sore

2

: to corrupt the spirit of

a relationship cankered by jealousy

intransitive verb

1

: to become infested with canker

2

: to become corrupted

Did you know?

Canker is commonly known as the name for a type of spreading sore that eats into the tissue—a use that obviously furnished the verb with both its medical and figurative senses. The word ultimately traces back to Latin cancer, which can refer to a crab or a malignant tumor. The Greeks have a similar word, karkinos, and according to the ancient Greek physician Galen, the tumor got its name from the way the swollen veins surrounding the affected part resembled a crab's limbs. Cancer was adopted into Old English, becoming canker in Middle English and eventually shifting in meaning to become a general term for ulcerations. Cancer itself was reintroduced to English later, first as a zodiacal word and then as a medical term.

Synonyms

Verb

• poison
• corrupt
• degrade
• deteriorate
• weaken
• damage

Examples of canker in a Sentence

Verb

such shameless ambulance chasing cankers the legal profession

Recent Examples on the Web

Noun

Fungal disease, butternut canker, wiped out about 90% of the state's butternut trees. —Jenna Prestininzi, Freep.com, 9 Oct. 2025

Pathogens including powdery mildew, gray mold, root rot, and stem rots/cankers can be a problem from time to time. —Kim Toscano, Southern Living, 3 Oct. 2025

Verb

Start by removing all blighted twigs and cankered branches 6 to 10 inches below the edge of visible infection. —Tim Johnson, chicagotribune.com, 1 Aug. 2019

Word History

Etymology

Noun and Verb

Middle English, from Anglo-French cancre, chancre, from Latin cancer crab, cancer

First Known Use

Noun

before the 12th century, in the meaning defined at sense 1a(1)

Verb

14th century, in the meaning defined at transitive sense 1

Phrases Containing canker

• canker sore
• citrus canker

Rhymes for canker

• anchor
• anker
• banker
• hanker
• rancor
• shanker
• tanker

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Kids Definition

canker

noun

can·​ker

ˈkaŋ-kər

1

: an often spreading sore that eats into tissue

2

a

: an area of dead tissue in a plant

b

: a plant disease marked by cankers

3

: any of various animal diseases marked especially by inflammation

cankerous

ˈkaŋ-k(ə-)rəs

adjective

Etymology

Noun

Middle English canker "spreading sore," from an early French dialect word cancre (same meaning), from Latin cancer "crab, cancer" — related to cancer, chancre see Word History at cancer

Medical Definition

canker

noun

can·​ker ˈkaŋ-kər 

1

a(1)

: an erosive or spreading sore

(2)

obsolete : gangrene

b

: canker sore

2

a

: a chronic inflammation of the ear in dogs, cats, or rabbits

especially : a localized form of mange

b

: a chronic and progressive inflammation of the deep horn-producing tissues of the frog and sole of the hooves of horses resulting in softening and destruction of the horny layers