Definition of tautology in English:



mass noun
  • 1The saying of the same thing twice over in different words, generally considered to be a fault of style (e.g. they arrived one after the other in succession).

    • ‘It is conceivable that the key to truth lies in tautology and redundancy.’
    • ‘Julian concurred that evenings set aside for communication with ‘dead angels’ (I'm sure there's some tautology in there) were right up his street and he couldn't believe he'd missed it.’
    • ‘Redundancy and tautology are undesirable, and a sign of less than careful writing.’
    • ‘The footpath outside the front of our house is flanked on both sides (is that tautology?) with low bushes.’
    • ‘But really, spinning out some kind of clever model to illustrate that idea is unnecessary tautology: I can say it in just a few simple words.’
    repetition, repetitiveness, repetitiousness, reiteration, redundancy, superfluity, periphrasis, iteration, duplication
    View synonyms
    1. 1.1count noun A phrase or expression in which the same thing is said twice in different words.
      • ‘Note the tautology in the first sentence, the feeble attempt at punnery.’
      • ‘But then, Coward himself was less refined than he thought: ‘The general consensus of opinion,’ he has Hugo say, two tautologies in a mere five words.’
      • ‘I'm not saying he is a sloppy reviewer, because the phrase ‘sloppy reviewer’ is a tautology when it comes to the press.’
      • ‘Incidentally, white jasmine is a tautology in the Indian context.’
    2. 1.2Logic A statement that is true by necessity or by virtue of its logical form.
      • ‘Some authors treated the quantity theory as a matter of causal relation and explanation, often differing as to the content and direction of explanation, whereas others saw it as a truism, identity or tautology.’
      • ‘This coinage has often provoked the accusation that nothing is really being asserted in the argument for natural selection: since fitness can only be defined by survival the phrase is a tautology.’
      • ‘Tautologies are statements true by definition and so are quite incapable of empirical refutation or prediction (insofar as a prediction in science must be empirically falsifiable).’
      • ‘It doesn't affect the validity of the statement, so you can include it without destroying your tautology.’
      • ‘The past, in effect, is a tautology; it is true by virtue of its logical form alone.’


Mid 16th century: via late Latin from Greek, from tautologos ‘repeating what has been said’, from tauto- ‘same’ + -logos (see -logy).