Definition of canker in US English:



  • 1A destructive fungal disease of apple and other trees that results in damage to the bark.

    • ‘Activity in the citrus orchards of central Queensland has ground to a halt as the state calls for help to deal with the mammoth task of inspecting trees for the disease canker.’
    • ‘In the first stage, 8,000 trees are being treated with a copper spray, to contain the canker when trees are chopped down and burnt.’
    • ‘But chief health officer Chris Adriaansen says states want trees in the quarantine area at Emerald individually inspected for canker.’
    • ‘It pays to be on the lookout for apple scab, canker and mildew, tackling any problems before they become deeply ingrained and hard to treat.’
    • ‘Trees appear to resist bacterial canker but are very susceptible to fire blight.’
    fungal disease, fungal rot, plant rot
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    1. 1.1 An open lesion in plant tissue caused by infection or injury.
      • ‘Punching holes around each canker, Cummings Carlson's team inoculated the tree with a slurry of hypovirulent fungus.’
      • ‘In dry edible beans, anthracnose causes unsightly cankers on plant stems, pods, and seeds.’
      • ‘He visits other chestnut trees, too, packing mud on their cankers and clipping flowers for use in breeding programs.’
      • ‘Removal of bark over the canker reveals a sharply defined region of darkened or discolored wood bordered by white, healthy wood.’
      • ‘As the infection progresses, trees undergo twig and branch dieback and develop stem cankers, which results in tree-death.’
    2. 1.2 Fungal rot in some fruits and vegetables, e.g. parsnips and tomatoes.
      fungal disease, fungal rot, plant rot
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  • 2An ulcerous condition or disease of a human or animal.

    ulcer, ulceration, infection, sore, running sore, lesion, abscess, chancre
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    1. 2.1North American A small ulcer of the mouth or lips.
      • ‘If your child's doctor prescribes a medicine that should be applied directly to the canker sore, first dry the area with a tissue.’
      • ‘Once it does, the canker sore may swell and burst in about a day.’
      • ‘When my husband was a little boy, the doctor told his mom he had a canker sore.’
      • ‘Most villagers show symptoms such as skin cankers as a result of breathing the poisonous air or drinking the polluted water over a long period.’
      • ‘Call your doctor if your child's canker sore gets worse.’
      • ‘This means that you swish the medicine around in your mouth, especially around your canker sore, for a few minutes before swallowing it.’
      sore, ulceration, open sore, abscess, boil, carbuncle, pustule, blister, cyst, gumboil, wen
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    2. 2.2
      another term for thrush (sense 2)
    3. 2.3 Ulceration of the throat and other orifices of birds, typically caused by a protozoal infection.
    4. 2.4 Inflammation of the ear of a dog, cat, or rabbit, typically caused by a mite infestation.
      • ‘Be sure to purchase ear canker powder as it has the additional benefit of helping to control canker and ear mites in your Shih Tzu.’
      • ‘It promotes healing and dries up the inner ear canker as well as the external areas that may become sore and moist from the canker discharge.’
      • ‘When we took our cat to the clinic yesterday, the vet told us that the ear mites were gone, but he thinks that the ear canker may be too strong for our cat and it caused irritation.’
      • ‘Whether or not ear mites are present, accumulated ear wax in a dog's ear can lead to ear canker and other serious infections.’
      • ‘Ear mite or ear canker is a very common infection in most rabbitries and is economically important because of the loss of condition and poor reproductive performance that this infestation can cause.’
      ulcer, ulceration, infection, sore, running sore, lesion, abscess, chancre
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  • 3A malign and corrupting influence that is difficult to eradicate.

    in singular ‘racism remains a canker at the heart of the nation’
    • ‘There is a certain pathological view about corruption, about the entire organ being diseased, about a canker in national character, a view which has no basis in facts.’
    • ‘The problem is the blind smugness of a society, and a political class, that see teenage violence simultaneously as a canker and an abstraction.’
    • ‘Anti-intellectualism is a hideous canker in our society, but it feeds on needless pretension and superiority.’
    • ‘Yet it is impossible not to recognise in the modern game an additional and growing canker that has attached itself to all the old familiar forms of dubious behaviour.’
    • ‘It is quite a remarkable thing for a novelist to name the canker that makes for human rottenness, especially since James does it with such fine literary craft and such acute theological discernment.’
    • ‘For politicians, the overstayer issue is a bit of a canker.’
    • ‘‘The frenzied addiction to art,’ wrote Baudelaire, is a canker that devours.’
    • ‘As music lovers might we not more frequently draw attention to this noise canker in our society?’
    • ‘‘That is the canker in the heart of the Conservative Party and that is what sparked the trouble,’ he said’
    • ‘Now the big question is how to curb the canker of corruption and restore much needed probity in public life.’
    • ‘His hurt never diminished and remained as a canker that ate away at him as he grew older.’
    blight, evil, scourge, poison, cancer, sickness, disease, pestilence, plague
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  • 1no object (of woody plant tissue) become infected with canker.

    ‘we found some cankering of the wood’
    • ‘Spring shoot growth on diseased canes is weak and stunted above the cankered area.’
    • ‘Tiny black specks, which are reproductive bodies of the cane blight fungus, develop in the brown cankered bark.’
    • ‘Stems may be girdled just above the soil line; tissue thus damaged may appear cracked or cankered.’
    • ‘Many larger trees showed cankered boles and parasite-bloated boughs.’
    • ‘Because of Adam's sin, the whole mass of mankind is cankered at the roots.’
  • 2as adjective cankeredInfected with a pervasive and corrupting bitterness.

    ‘he hated her with a cankered, shameful abhorrence’
    • ‘I'm a 37-year-old graduate student who's having the usual dating difficulties common among those of us who are old and grey and cankered.’
    • ‘Your gold and silver is cankered; and the rust of them shall be a witness against you, and shall eat your flesh as it were fire.’
    • ‘I mean, you know, irony's funny and all, but if all you do is make fun of other things, you get this kind of cankered, empty feeling.’


Middle English (denoting a tumor): from Old French chancre, from Latin cancer ‘crab’ (see cancer).