Definition of fallacious in English:



  • Based on a mistaken belief.

    ‘fallacious arguments’
    • ‘Speculation that MMR could be replaced by a series of individual vaccines was based on fallacious reasoning and would return Britain to the ‘dark ages’, he said.’
    • ‘However, a careful examination of the proposed agreement exposes this argument as fallacious.’
    • ‘We believe that argument to be absurd and fallacious, and hope that defenders of liberty will recognise that it is exactly this kind of panic-stricken measure that will most gratify the killers.’
    • ‘Nonetheless, he has worked his way to becoming a committed supporter of free trade; and, in the two books we have here to consider, he refutes a large number of fallacious arguments in favor of trade restrictions.’
    • ‘The important things about being skeptical are therefore understanding rational argument and understanding fallacious and fraudulent argument.…’
    • ‘The utterly fallacious idea at the heart of the pro-war argument is that it is the duty of the anti-war argument to provide an alternative to war.’
    • ‘However, most of his evidence is in the form of specious and fallacious arguments.’
    • ‘Alex is hawk-eyed when it comes to spotting lazy reasoning or fallacious argument, and lightning-fast at exposing it where it occurs.’
    • ‘Some of Descartes' claims were fallacious such as his belief that the velocity of light is infinite.’
    • ‘As ever the Telegraph is busy fulmigating against so many straw men and other fallacious arguments.’
    • ‘This argument is simply fallacious as both purposes can simultaneously apply.’
    • ‘Subscribers and practitioners of these fallacious beliefs were deemed at the time to be ‘properly schooled in science.’’
    • ‘Both the settlers and the far left believed that the disengagement could not take place because each group was gripped by a fallacious belief system, in which contradiction or dissent was impossible.’
    • ‘SIR - The campaign to save and restore the Odeon has been widely supported, but despite this, Bradford Centre Regeneration has advanced fallacious arguments that the scheme would prove too costly.’
    • ‘It is also a fallacious argument that heavy vehicles alone account for the recurring accidents.’
    • ‘If you stop to think about it, this argument is totally fallacious.’
    • ‘As this magazine reluctantly pointed out at the time, it is based on a fallacious theory that the brain works in strict hierarchical order: that the midbrain develops before the cortex.’
    • ‘The proofs are anecdotal or based on fallacious reasoning such as thinking that a correlation proves a causal connection.’
    • ‘I think this is an entirely fallacious argument, with little to no factual support.’
    • ‘Now that I have covered his central arguments as fallacious, I would like to step back and look at the work as a whole.’
    erroneous, false, untrue, wrong, incorrect, faulty, flawed, inaccurate, inexact, imprecise, mistaken, misinformed, misguided, misleading, deceptive, delusive, delusory, illusory, sophistic, specious, fictitious, spurious, fabricated, distorted, made up, trumped up
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Early 16th century: from Old French fallacieux, from Latin fallaciosus, from fallacia (see fallacy).