Definition of blackleg in English:



  • 1British derogatory A person who continues working when fellow workers are on strike; a strike-breaker.

    ‘the blacklegs who had arrived by rail were harassed by crowds of workers’
    as modifier ‘blackleg labour’
    • ‘Grassroots peasant activists burned crops, mined and barricaded roads, derailed trains, set fire to buildings, beat up strikebreakers and punctured the tyres of blackleg drivers.’
    • ‘The marital crisis coincides with a miners' strike in which the men are forced to live off a pittance while blacklegs take over their jobs.’
    • ‘They were ill organized, and defeated by the import of blackleg labour and drought, which struck in 1905.’
    • ‘When the newspaper called them ‘desperate rascals, thieves, robbers, cut-throats, and blacklegs’ the newspaper's editors were not far from the truth.’
    • ‘They are known as ‘Scummers’, a term going back to a dock strike in the fifties, when blackleg labour was brought in to breach the picket lines.’
    • ‘In response to his letter, I wholeheartedly disagree with his comments about ‘scabs’, ‘non-strikers’ and ‘blacklegs’.’
    • ‘There was no violence directed against the many blacklegs who drove buses and engaged in other strike-breaking activities.’
    • ‘They sang the Red Flag and the Marseillaise, followed by three cheers for the social revolution and three boos for royalty and blacklegs.’
    • ‘At the beginning of the 20th century, the picket was mainly concerned with preventing blackleg labour from being taken in to replace strikers.’
    • ‘Go on strike by all means, but don't be surprised if some unknown blackleg wannabe steals your job.’
  • 2mass noun An acute infectious bacterial disease of cattle and sheep, causing necrosis in one or more legs.

    The bacterium is Clostridium chauvoei

    • ‘The researcher said cases of blackleg often increased when animals moved to new pastures.’
    • ‘You can't pretend the wheat doesn't have head blight, a cow doesn't have blackleg, or that predators don't prey.’
    • ‘The clinical signs of botulism in cattle are caused by the toxin produced by a bacteria, which is in the same group that causes such familiar diseases as tetanus and blackleg.’
    • ‘Such other clostridials include black disease, blackleg, braxy, bacterial redwater and tetanus.’
    • ‘After the wet start, and now an increasingly wet end to the season, blackleg is being found more widely, and as soils approach field capacity more rots will appear.’
  • 3mass noun Any of a number of plant diseases in which part of the stem blackens and decays.

    a bacterial disease of potatoes (caused by Erwinia carotovora subsp. atroseptica).

    a fungal disease of cabbages and related plants (caused by Leptosphaeria, Pleospora, and other genera).

    • ‘This will ensure that any future overcoming of resistance does not result in the complete collapse of the cultivar from blackleg disease as now occurs in some field situations.’
    • ‘Since chemical control of the disease poses risks to the producer and the environment, the introduction of genetic resistance to blackleg has become a major objective of canola breeding programs.’
    • ‘Although numerous studies suggest that seedling and adult blackleg resistances are under different genetic controls, many authors have observed a significant correlation between the two.’
    • ‘The models revealed telling facts about the spread of anthracnose, blackleg and black spot.’
    • ‘There is no chemical cure and all growers can do is let the crop mature and hope the blackleg tubers will rot out.’


[no object]British
  • Continue working when one's fellow workers are on strike.

    • ‘The party's organic hostility to the working class soon proved of value to the bourgeoisie when it blacklegged on the 1980 general strike, which was broken by the government.’
    • ‘Second, the left decided to scab and blackleg on the ethnic group, whose struggle is the oldest cause of the left in the region.’


Early 18th century (in the sense ‘infectious disease of cattle and sheep’): from black + leg. The sense ‘strike-breaker’ dates from the mid 19th century; it may derive from an earlier sense ‘swindler, cheat’, with possible comparison to a crow or rook, black birds regarded as having thieving habits.