illogical
Americanadjective
adjective
-
characterized by lack of logic; senseless or unreasonable
-
disregarding logical principles
Other Word Forms
Etymology
Origin of illogical
Explanation
When there's no good reason or explanation for something, don't fret; chances are it's illogical — meaning that it has no rational explanation behind it. The word logic has origins in the Greek root logos meaning "reason, idea, or word." But slap the prefix il- in front of it, and suddenly the word reverses its meaning. Illogical? Check out other words with the same prefix, like illegitimate and illegal, and you'll quickly see that the prefixil- in front of a word starting in "l" means "not." Suddenly the meaning of illogical isn't quite so illogical after all, is it?
Vocabulary lists containing illogical
Inside Out & Back Again
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The Devil's Arithmetic
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Way Off: Synonyms for "Wrong"
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
"The sites we've currently explored are in south-west Ireland, but it's illogical to presume that early humans just bypassed Wexford, Waterford and Cork, and ploughed on west," said Nash.
From BBC ● Sep. 4, 2026
The results may help explain behavior that can otherwise seem illogical in daily life.
From Science Daily ● Aug. 13, 2026
But if you sense a pattern of instability and see some illogical decisions being made, it might be smart to apply for other roles.
From MarketWatch ● Jun. 12, 2026
Please forgive this exercise in premise-granting, but this is where the theorized plot against Pratt goes from incoherent to illogical.
From Slate ● Jun. 9, 2026
It was a preposterous idea, illogical, and yet...she remembered the building pressure in her chest, followed by that brilliant sense of release.
From "Beasts of Prey" by Ayana Gray
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Get a wordDefinitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
