tautology - Wiktionary, the free dictionary
English
Noun
tautology (countable and uncountable, plural tautologies)
- (uncountable, rhetoric) Redundant use of words, a pleonasm, an unnecessary and tedious repetition.
- ✤ It is tautology to say, “Forward Planning”.
- (countable, rhetoric) An expression that features tautology.
- ✤ The expression “raze to the ground” is a tautology, since the word “raze” includes the notion “to the ground”.
- ✤ Pure mathematics consists of tautologies, analogous to ‘men are men’, but usually more complicated.1
- (countable, logic, propositional logic) A statement that is true for all truth values of its propositional variables.
- (countable, logic, first-order logic) A statement that is true for all truth values of its Boolean atoms.
Etymology
From Late Latin tautologia, from Ancient Greek ταὐτολογία (tautología) from ταὐτός (tautós, “the same”) + λόγος (lógos, “explanation”). By surface analysis, tauto- + -logy.
Pronunciation
- (Received Pronunciation) IPA: /tɔːˈtɒləd͡ʒi/
- (Standard Southern British, Australia, New Zealand) IPA: /toːˈtɔləd͡ʒi/
- Audio (Southern England): 🔊
- (US)
- (without the cot–caught merger) IPA: /tɔˈtɑləd͡ʒi/
- (cot–caught merger) IPA: /tɑˈtɑləd͡ʒi/
- Audio (General American, cot–caught merger): 🔊
- (Scotland) IPA: /tɔˈtɔləd͡ʒe/
- Rhymes: -ɒlədʒi
Printed 2026-09-04.
(echo:: @ ⌗)
Footnotes
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1946, Bertrand Russell, History of Western Philosophy: ↩