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Puzzle of the Day #21

#21 · Friday 16 October 2026. A new classic brain teaser every day, credited to where it comes from.

Is the word 'heterological' heterological?

Call a word 'autological' if it describes itself, like 'short' (which is short) or 'English' (which is English). Call it 'heterological' if it doesn't, like 'long' (which isn't long) or 'monosyllabic' (which isn't one syllable). Now ask: is the word 'heterological' itself heterological?

Reveal the answer

Either answer breaks the rule. If 'heterological' is heterological, then by its own definition it must not describe itself, so it should be autological instead. If it's autological, it must describe itself, meaning it is heterological after all. Kurt Grelling and Leonard Nelson published the paradox in 1908 as a language-based cousin of Russell's Barber Paradox, showing that self-reference can trip up ordinary adjectives, not just sets.

— Kurt Grelling and Leonard Nelson, Bemerkungen zu den Paradoxien von Russell und Burali-Forti — 1908

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