deduce
Americanverb (used with object)
verb
-
(may take a clause as object) to reach (a conclusion about something) by reasoning; conclude (that); infer
-
archaic to trace the origin, course, or derivation of
Other Word Forms
Derived Forms
-
deducibilitynoun
-
deduciblenessnoun
-
deducibleadjective
-
nondeducibleadjective
-
subdeducibleadjective
-
undeducedadjective
-
undeducibleadjective
-
deduciblyadverb
Inflected Forms
Participles
Conjugated Forms
Present
-
deducesimple
-
deducessimple
-
have deducedperfect
-
has deducedperfect
-
am deducingprogressive
-
are deducingprogressive
-
is deducingprogressive
-
have been deducingperfect progressive
-
has been deducingperfect progressive
Past
-
deducedsimple
-
had deducedperfect
-
was deducingprogressive
-
were deducingprogressive
-
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
The Vocabulary.com Top 1000
Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!
Jim Burke's Academic Vocabulary List
Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!
Lead the Way: Duc and Duct
Want to remember this word for good? Start your learning journey today with our library of interactive, themed word lists built by the experts at Vocabulary.com – we'll help you make the most of your study time!
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:
As we deduce from the phone calls Maxine makes back home, she’s also going through an acrimonious divorce and has trouble connecting with her blasé teenage daughter.
From Los Angeles Times ● Jun. 26, 2026
This gives scientists a brief chance to measure how the more stable elements decay, then deduce the properties of the original particle.
From Barron's ● Mar. 17, 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
Rationalists—like lawyers relying on “common sense” reasoning—believe we can deduce truth from first principles.
From Slate ● Sep. 26, 2025
To understand the basic outline of this technique, imagine trying to deduce the shape of a minute three-dimensional object—a cube, say.
From "The Gene" by Siddhartha Mukherjee
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
But Bron is also, as Daniel Craig’s Benoit Blanc eventually deduces, an idiot.
From Seattle Times ● Mar. 7, 2023
This kind of wearable device uses green light to detect blood flow beneath your skin and deduces your heart rate.
From Salon ● Dec. 31, 2022
He looks around and deduces that, in this very moment, he’s a character in a play that’s currently being written by Gunderson.
From Los Angeles Times ● Feb. 4, 2021
Because he saw that Major Rathbone’s wounds were caused by a knife, and because he hadn’t heard any gunshots during the performance, Leale deduces that Lincoln was stabbed.
From "Lincoln's Last Days: The Shocking Assassination that Changed America Forever" by Bill O'Reilly
After scouring job postings online and talking with local ranchers, he’s deduced that the land might soon be transformed into one of the many large-scale data centers moving into Montana over the past year.
From The Wall Street Journal ● Jul. 11, 2026
"We've kind of deduced it to be UVC radiation, the radiation that exists above the ozone layer because obviously there's no filter up there", he says.
From BBC ● Apr. 29, 2026
The analysts split out the ETFs that they deduced retail investors put their money in.
From MarketWatch ● Dec. 4, 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
On every wall hung Historical Portraits so shameless in their Overuse of Symbolism that any first-year art student could have deduced where they were.
From "The Hidden Gallery" by Maryrose Wood
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
But Xu argues that the yuck factor is not a sound basis for deducing what's ethical and what's not.
From Salon ● May 13, 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
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.