English
fallacy
Fallacy comes from Latin fallācia ‘deception, deceit’, and goes back to fallō.
- Latinc. 75 BCE–200 CEfallō1as fallere‘to deceive’
- Latinc. 75 BCE–200 CEfallāx1‘deceptive, deceitful’
- Latinc. 75 BCE–200 CEfallācia1‘deception, deceit’
- Old Frenchc. 842–1400fallace1
- Middle Englishc. 1150–1500fallaci1
- Englishearliest quotation 1749fallacy1
attested reconstructed ? uncertain or disputed deepest recorded ancestor
- 1 Wiktionary, English fallacy
- Earliest quotation in Wiktionary’s entry: 1749, Henry Fielding, The History of Tom Jones: “Mr Jones expressed great gratitude to the lady for…”.
Earlier history uncertain. See Wiktionary.
Lineage
- Latinc. 75 BCE–200 CEfallōWiktionary, English fallacyas fallere‘to deceive’
- Latinc. 75 BCE–200 CEfallāxWiktionary, English fallacy‘deceptive, deceitful’
- Latinc. 75 BCE–200 CEfallāciaWiktionary, English fallacy‘deception, deceit’
- Old Frenchc. 842–1400fallaceWiktionary, English fallacy
- Middle Englishc. 1150–1500fallaciWiktionary, English fallacy
- Englishearliest quotation 1749fallacyWiktionary, English fallacy. Earliest quotation in Wiktionary’s entry: 1749, Henry Fielding, The History of Tom Jones: “Mr Jones expressed great gratitude to the lady for…”
Formed from -acy
Linked words
through Proto-Indo-European *(s)gʷʰh₂el- ‘to stumble’
through Proto-Italic *falsō
fail, default, falsely, falsetto, 6 more
through Latin fallō ‘to deceive’
failure, fault, false, faux, falsify, fallible, falsity, 9 more
Today it means
noun Deceptive or false appearance; that which misleads the eye or the mind.
Sources
Sources: Wiktionary, “fallacy”. By Wiktionary contributors, CC BY-SA 4.0, via kaikki.org (dump of Oct 3 2026); text adapted and restructured. Language periods are conventional ranges, not dates for this word. License.
Etymograph / Latin fallō / fallacy