deduce
Americanverb (used with object)
verb
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(may take a clause as object) to reach (a conclusion about something) by reasoning; conclude (that); infer
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archaic to trace the origin, course, or derivation of
Other Word Forms
Derived Forms
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deducibilitynoun
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deduciblenessnoun
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deducibleadjective
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nondeducibleadjective
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subdeducibleadjective
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undeducedadjective
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undeducibleadjective
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deduciblyadverb
Inflected Forms
Participles
Conjugated Forms
Present
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deducesimple
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deducessimple
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have deducedperfect
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has deducedperfect
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am deducingprogressive
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are deducingprogressive
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is deducingprogressive
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have been deducingperfect progressive
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has been deducingperfect progressive
Past
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deducedsimple
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had deducedperfect
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was deducingprogressive
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were deducingprogressive
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had been deducingperfect progressive
Future
Etymology
Origin of deduce
First recorded in 1520–30; from Latin dēdūcere “to lead down, derive,” from dē- de- + dūcere “to lead”
Explanation
To deduce is to figure something out based on what you already know. When you see a person crying, it's easy to deduce that the person is sad. Unless they're happy, of course. Sometimes happy people cry. Derived from the Latin ducere, meaning "to lead," a person who deduces something is "leading" their mind from one idea to the next. Deduction is a noun from the verb deduce: it's what we call something that we learn when we deduce. Sherlock Holmes, the famous investigator created by Arthur Conan Doyle, was a master of deduction. He could deduce from a few small clues all of the facts of a murder case.
Vocabulary lists containing deduce
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Lead the Way: Duc and Duct
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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.
See Examples For:
Don’t waste one brain cell trying to deduce the assassin.
From Los Angeles Times ● Jun. 5, 2026
The WHO was trying to deduce how hantavirus had appeared on the ship, with the first person who died having developed symptoms on April 6.
From Barron's ● May 5, 2026
The detective and his team deduce that the plotters likely include government and industry officials in Canada and the U.S., as well as organized-crime figures and even members of the Quebec police force.
From The Wall Street Journal ● Nov. 14, 2025
So what can we deduce from all of this?
From BBC ● Oct. 16, 2025
“Well, they try to deduce all of mathematics from simple logical principles and show that mathematics is really based on logic. It’s pretty complicated stuff. But I enjoy it.”
From "The Chosen" by Chaim Potok
But Igor isn’t just adept at sniffing out truffles — he quickly deduces that she’s emotionally lost.
From Los Angeles Times ● Nov. 14, 2025
Then, with what it deduces about an individual's personality, the AI overlays that on top of what advertisers already know about people.
From BBC ● Nov. 13, 2025
When one starts barking orders in Arabic, Sam quickly deduces that he is merely trying to communicate with passengers on a plane that just took off from Dubai.
From New York Times ● Jun. 27, 2023
But Bron is also, as Daniel Craig’s Benoit Blanc eventually deduces, an idiot.
From Seattle Times ● Mar. 7, 2023
Marie-Laure deduces what she can from the sounds of their shoes: those are small, those weigh a ton, those hardly exist at all.
From "All the Light We Cannot See" by Anthony Doerr
The analysts split out the ETFs that they deduced retail investors put their money in.
From MarketWatch ● Dec. 4, 2025
On the subject of lyricism, as may be deduced by now, it was a largely disappointing year for new musicals—but not for musical-theater performances.
From The Wall Street Journal ● Nov. 26, 2025
From this, they deduced that DNA must have a three-dimensional, double-helix structure - like a twisted ladder with rungs formed of alternating salt and phosphate groups.
From BBC ● Nov. 7, 2025
He confidently illustrates what he’s deduced by drawing a grid on a whiteboard and yammering as his suspects and colleagues watch, slack-jawed.
From Salon ● Mar. 26, 2025
Salim was laughing and nudging Kat so I deduced that he was not bored, although I would have been.
From "The London Eye Mystery" by Siobhan Dowd
These include age verification tools such as facial age estimation, which must be "robust" in deducing whether a user is over 18.
From BBC ● Nov. 20, 2025
He soon reemerged, correctly deducing that there will always be starry-eyed sports fans willing to overlook pervasive failings.
From Slate ● May 29, 2024
The IRS doesn’t track the race or ethnicity of taxpayers, but researchers used a methodology of deducing race by name and geography.
From Washington Times ● May 15, 2023
“It’s like deducing the properties of unobserved dark matter by looking at its gravitational effects.”
From Science Magazine ● Jul. 20, 2022
Am I right in deducing that these charges were incurred by you?
From "The Long-Lost Home" by Maryrose Wood
Definitions 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.
