I'm sure I've heard a verb that means this, but it might be colloquial, and possibly quite specific to a certain group of people.

The context is that person 'A' has tried to give a precise definition of some grand concept. For example, 'A' says "life can be defined as any system that maintains a low entropy by degrading an energy source" Person 'B' then gives a counterargument along the lines of "ah, but under that definition, wouldn't a candle flame also be considered alive?" In other words, 'B' has satisfied 'A's definition, but not in a way that 'A' will like, thus forcing 'A' to change her definition. 'B' can then be said to have ____ed 'A's original definition.

As Brian Donovan points out in a comment, the classic example is that when Plato defined 'human being' as 'featherless biped', Diogenes produced a plucked chicken, causing Plato to amend his definition. (To 'featherless biped with fingernails'.)

The word might also refer more generally to giving someone what they've asked for, but according to the letter rather than the spirit of what they said, thus not actually being what they wanted at all.

Invalidating a definition in this way is a special case of reductio ad absurdum of course, but I'm looking for a word that specifically describes this case.

I'm also not looking for general words meaning to invalidate or disprove; the word I'm thinking of (if it exists) refers very specifically to the case of showing that a definition is more broadly applicable than was originally intended.

The word I'm looking for (still, nearly three years later) might be somewhat humorous in nature.

  • possibly this would be more at home on philosophy.SE - please let me know if that's the case – Nathaniel Jul 17 '15 at 15:53
  • In mathematics, they're called degenerate cases. Like the degenerate conic sections. – John Lawler Jul 17 '15 at 15:57
  • @JohnLawler that isn't quite what I'm after - degenerate cases are cases which satisfy definitions in "unsatisfying" ways, but which are tolerated because they make things simpler. I'm talking about cases where the definition actually has to be changed because of them. For example, if someone showed that your definition of life included flames, you would have to change your definition. (Or accept that flames are in fact alive - but most people would not be willing to do that.) This doesn't happen much in maths because you're generally free to define things how you want. – Nathaniel Jul 17 '15 at 16:09
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    The classic case is when Plato defined human being as featherless biped and Diogenes produced a plucked chicken. – Brian Donovan Jul 17 '15 at 16:46
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    Tellingly, your edit includes the verb invalidate suggested several hours previously by Tushar Raj. – Mari-Lou A Jul 18 '15 at 14:34

B has refuted/invalidated/disproved/debunked A's definition.

  • refute: Prove (a statement or theory) to be wrong or false; disprove

  • invalidate: Make or prove (an argument, statement, or theory) unsound or erroneous

  • disprove: Prove that (something) is false

  • debunk: Expose the falseness or hollowness of (an idea or belief):


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    +1 I think invalidate fits this well. It can be used in the OP's example and also in Brian Donovan's example 'Diogenes invalidated Plato's definition'. – landocalrissian Jul 17 '15 at 17:10
  • +1 so many is too many though. – weakphoneme Jul 19 '15 at 15:03
  • What's up, Tushar Raj? – user98990 Jul 24 '15 at 17:47
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    @LittleEva: Hi. I've been swamped. Nay, quicksanded. Avalanched. I'll return soon as i can. – Tushar Raj Jul 27 '15 at 7:19
  • Glad to hear you're still with us Tushar, ping me when you can. :-) – user98990 Jul 31 '15 at 16:28

The first word that came to my mind was "torpedoed". The second example at Merriam-Webster is

Her injury torpedoed her goal of competing in the Olympics.

It has more of the negative connotation than the "satisfaction" criteria of the question, but just another option.


Perhaps B has brought up a technicality. B might be playing Devil's advocate.


'B' has contradicted 'A's original definition:

1.1 Assert the opposite of a statement made by (someone):
he did not contradict her but just said nothing
within five minutes he had contradicted himself twice


A asserted specific qualities as the definition of life, but B asserts that those qualities are unfit to define life by satisfying A's definition with an absurd conclusion.


For the examples given, "reified" might work. In the examples something abstract or conceptual (pure) is being degraded or diluted by extending it to the concrete.

He reified my elegant concept with vulgar particulars.

Reify: to treat (an abstraction) as substantially existing, or as a concrete material object. Origin of reify. ; from Classical Latin res, thing (see real) + -fy. (Yourdictionary.com)

Reification (fallacy), the fallacy of treating an abstraction as if it were a real thing (Wikipedia)



person A provides a definition of "life", person B's interpretation to the letter falsifies the previous definition.

'B' can then be said to have falsified 'A's original definition.

Alternatively, if person B successfully contests A's argument, B has demonstrated that it is flawed. Thus B challenges A's definition, A is forced to review and reassess their previous statement however contrived B's counterargument may have been, consequently A's argument is now incontestable (impossible to question because of being obviously true.)


What you cite could be called an instance of the Socratic method or elenchus, although both Socratic method and elenchus encompass more than mere analysis of concepts or definitions.

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