Definition of Godwin's law in US English:

Godwin's law

noun

humorous
  • The theory that as an online discussion progresses, it becomes inevitable that someone or something will eventually be compared to Adolf Hitler or the Nazis, regardless of the original topic.

    ‘correcting others' errors, especially online, can quickly lead to invocations of Godwin's law’
    • ‘Yet more evidence that Godwin's Law extends well past the confines of the Internet.’
    • ‘On second thoughts, stuff Godwin's Law: I will mention the war because it is thunderously relevant.’
    • ‘But I think I've already violated Godwin's Law enough for one week.’
    • ‘The comments are your usual online argument that even borders on Godwin's Law.’
    • ‘It used to be that any hope for a reasonable debate was ended the second anyone called someone else a "Nazi" (see Godwin's Law).’
    • ‘You know it's quite difficult to contain the impulse to break Godwin's Law when I read things like this.’
    • ‘Godwin's Law has been invoked (again).’
    • ‘At the risk of being accused under Godwin's Law, I agree.’
    • ‘Godwin's Law thus practically guarantees the existence of an upper bound on thread length in those groups.’
    • ‘Sadly, he breaks Godwin's Law near the end.’
    • ‘But someone really ought to have warned him about Godwin's Law.’
    • ‘It was Godwin's law in action.’
    • ‘Isn't that the lawyer's equivalent of Godwin's Law?’
    • ‘But there seems to be something there that turns normally intelligent, open-minded people rabid, with Godwin's Law coming into play at about the third post.’
    • ‘Do I get an extra point for being the first to invoke Godwin's Law?’
    • ‘I look forward to the discussion my choices provoke and the number of irate emails I get before Godwin's Law comes into play.’
    • ‘If there were ever a perfect example of a blog post title that violates Godwin's law, I reckon this is it.’
    • ‘We're about a heart-beat from Godwin's Law, here.’
    • ‘That has to be a record for the longest period of time before Godwin's Law kicks in.’
    • ‘How do we talk about these things without running afoul of Godwin's Law?’

Origin

1990s: named after Mike Godwin (b.1956), the US lawyer and author who originated the theory.