paradox

noun

1. (countable, uncountable)An apparently self-contradictory statement, which can only be true if it is false, and vice versa.

   “"This sentence is false" is a paradox.”

   “The active sense of living which we all enjoy, before reflection shatters our instinctive world for us, is self-luminous and suggests no paradoxes.”

   “According to one version of an ancient paradox, an Athenian is supposed to say "I am a liar." It is then argued that if the statement is true, then he is telling the truth, and is therefore not a liar […]”

2. (countable, uncountable)A counterintuitive conclusion or outcome.

   “It is an interesting paradox that drinking a lot of water can often make you feel thirsty.”

   “The most fundamental paradox is that if we're never to use force, we must be prepared to use it and to use it successfully.”

3. (countable, uncountable)A claim that two apparently contradictory ideas are true.

   “Not having a fashion is a fashion; that's a paradox.”

   “How quaint the ways of Paradox! / At common sense she gaily mocks! / Though counting in the usual way years twenty-one I've been alive, / Yet reck'ning by my natal day, / Yet reck'ning by my natal day, / I am a little boy of five!”

4. (countable, uncountable)A thing involving contradictory yet interrelated elements that exist simultaneously and persist over time.
5. (countable, uncountable)A person or thing having contradictory properties.

   “He is a paradox; you would not expect him in that political party.”

   “You are a paradox of bitch and angel.”

6. (countable, uncountable)An unanswerable question or difficult puzzle, particularly one which leads to a deeper truth.

   “And only by dismantling our preconceptions of age can we be free to understand the paradox: How young are the old?”

7. (countable, obsolete, uncountable)A statement which is difficult to believe, or which goes against general belief.

   “Ay, truly; for the power of beauty will sooner / transform honesty from what it is to a bawd than the / force of honesty can translate beauty into his / likeness: this was sometime a paradox, but now the / time gives it proof.”

   “they contended to make that Maxim, that there is no faith to be held with Infidels, a meere and absurd Paradox [...].”

8. (uncountable)The use of counterintuitive or contradictory statements (paradoxes) in speech or writing.

   “The need for paradox is no doubt rooted deep in the very nature of the use we make of language.”

9. (uncountable)A state in which one is logically compelled to contradict oneself.

   “Thus, like modern disputants, they aimed either to confute the respondent or to land him in paradox.”

10. (countable, uncountable)The practice of giving instructions that are opposed to the therapist's actual intent, with the intention that the client will disobey or be unable to obey.

    “Defiance-based paradox is employed so that the family will actively oppose and deliberately sabotage the prescription.”