English Reference
noun

paradox

n.
US /ˈpɛɹəˌdɑks/ UK /pˈæɹədˌɒks/ para·dox UK spelling paradox's, paradoxes

  1. 01 B2 Upper Intermediate Academic Science

    a statement that seems to say two opposite things at once, making it seem impossible.

    a statement that is apparently self-contradictory or logically unacceptable but may express a latent truth.

    Simple

    The 'liar paradox' is a famous example: if I say 'I am lying,' am I telling the truth?

    In context

    The twin paradox in physics challenges our intuitive understanding of time by suggesting that a space traveller would age more slowly than their earthbound sibling.

    Usage

    Often used with 'the' to refer to specific named problems in logic or science.

  2. 02 B2 Upper Intermediate

    a situation that has two opposite qualities that make it difficult to understand.

    a situation or event that combines contradictory features or qualities.

    Simple

    It is a paradox that such a wealthy country has so many people living in poverty.

    In context

    The paradox of the modern workplace is that despite having more labour-saving technology than ever, employees report feeling more overworked than previous generations.

  3. 03 C1 Advanced Literary

    a person who has qualities that do not seem to go together.

    a person whose character or behaviour is composed of seemingly incompatible traits.

    Simple

    He is a paradox: a very shy man who loves performing on stage in front of thousands.

    In context

    The novelist was a fascinating paradox, known for her ruthless public persona while privately maintaining a reputation for extraordinary generosity and warmth.

This puzzle—a balmy Earth under a cooler, dimmer sun—is known as the Faint Young Sun paradox.

Phys.org· 24 Aug 2026

From Middle French paradoxe, from Latin paradoxum, from Ancient Greek παράδοξος (parádoxos, “unexpected, strange”).

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Origin Ancient Greek παράδοξος
Level B2 · Upper Intermediate
Frequency Frequent
Updated