Fallacious
/fəˈleɪ.ʃəs/noun
Deceptive or based on a mistaken belief or invalid reasoning.
Did you know?The word comes from Latin fallax, meaning “deceitful,” from fallere, “to deceive,” a root that also lies behind words for fraud and failure in several Romance languages.
Etymological Timeline
Proto-Indo-European
PIE
*bʰel-
“to deceive, cheat, or betray”
Latin
Latin
fallere
“to trip up, deceive, or disappoint”
Latin
Latin
fallax
“deceitful, misleading”
Late Latin
Latin
fallaciosus
“full of deceit; deceptive”
Middle English
English
fallacious
“deceptive; misleading”
Modern English
English
fallacious
“based on a mistaken belief or invalid reasoning”