deduction

[ dih-duhk-shuhn ]

See synonyms for deduction on Thesaurus.com

noun

the act or process of deducting; subtraction.
something that is or may be deducted: She took deductions for a home office and other business expenses from her taxes.

the act or process of deducing.
something that is deduced: His astute deduction was worthy of Sherlock Holmes.
Logic.
- a process of reasoning in which a conclusion follows necessarily from the premises presented, so that the conclusion cannot be false if the premises are true.
- a conclusion reached by this process.: Compare induction (def. 4).

Origin of deduction

First recorded in 1400–50; late Middle English deduccioun, from Anglo-French, from Latin dēductiōn-, stem of dēductiō “a leading away”; see deduct, -ion

Other words from deduction

non·de·duc·tion, noun
pre·de·duc·tion, noun

Words that may be confused with deduction

deduction , extrapolation, induction, generalization, hypothesis

Words Nearby deduction

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use deduction in a sentence

Tim Scott, a Republican senator from South Carolina, introduced the deduction, claiming it would help restaurants and restaurant workers who have been struggling since the beginning of the pandemic.
The “three-martini lunch” tax break sums up why so many people hate capitalism | Lila MacLellan | December 21, 2020 | Quartz
In other words, employers can claim a large portion of the cost of some AI up front as a tax deduction.
It’s time to rethink the legal treatment of robots | Emily Luong | October 22, 2020 | MIT Technology Review
In addition to avoiding wage taxes, businesses can accelerate tax deductions for some AI when it has a physical component or falls under certain exceptions for software.
It’s time to rethink the legal treatment of robots | Emily Luong | October 22, 2020 | MIT Technology Review
If you squeeze the last drop of deduction from the puzzle conditions, you won’t have too many trial-and–error candidates to search through.
Celebrating the Playful Magic of John Horton Conway | Pradeep Mutalik | October 15, 2020 | Quanta Magazine
In addition, the TCJA gives individuals several tax breaks—an increased child tax credit and standard deduction, for example—that are scheduled to expire at the end of 2025.
What business needs from the 2020 election | Geoffrey Colvin | September 30, 2020 | Fortune

That would have involved overturning a 1977 Court decision that upheld automatic deduction of union dues.
Only Eight Years of President Hillary Can Take the Supreme Court Away From Conservatives | Michael Tomasky | June 30, 2014 | THE DAILY BEAST
True, making an Item 24 deduction requires me to “Attach Form 2106.”
Up to a Point: I Do My Own Taxes With No Help, Except From a Couple of Bloody Marys | P. J. O’Rourke | April 15, 2014 | THE DAILY BEAST
The devil was predictably in the details, with a surcharge on the rich and a call to end the state and local tax deduction.
RIP: Obama’s Grand Bargain With the GOP on Entitlements | John Avlon | March 2, 2014 | THE DAILY BEAST
Apparently, not much has really changed since Bill took a $2 tax deduction for each pair of underwear that he donated to charity.
The Clintons Can’t Shake Their Reputation for Ethical Shadiness | Lloyd Green | September 19, 2013 | THE DAILY BEAST
To my mind, this is why we should get rid of the corporate income tax--and the charitable tax deduction as well.
When the Personal Becomes Political | Megan McArdle | June 12, 2013 | THE DAILY BEAST
This was considered by the Post-office Department as an average deduction of 53 per cent.
The Postal Service of the United States in Connection with the Local History of Buffalo | Nathan Kelsey Hall
The amount so collected was to be paid to the tithe-owners, subject to a deduction of three per cent.
The History of England in Three Volumes, Vol.III. | E. Farr and E. H. Nolan
Does he prove that criminal procedure against the colonies would fail, by sign or by deduction?
English: Composition and Literature | W. F. (William Franklin) Webster
The great conclusions are reached by the certain methods of elimination and deduction.
English: Composition and Literature | W. F. (William Franklin) Webster
No more logical deduction was possible than this commencement of decentralization within the Prussian monarchy.
Great Men and Famous Women. Vol. 4 of 8 | Various

British Dictionary definitions for deduction

deduction

/ (dɪˈdʌkʃən) /

noun

the act or process of deducting or subtracting
something, esp a sum of money, that is or may be deducted

- the process of reasoning typical of mathematics and logic, whose conclusions follow necessarily from their premises
- an argument of this type
- the conclusion of such an argument
logic
- a systematic method of deriving conclusions that cannot be false when the premises are true, esp one amenable to formalization and study by the science of logic
- an argument of this type: Compare induction (def. 4)

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for deduction

deduction

[ dĭ-dŭk′shən ]

The process of reasoning from the general to the specific, in which a conclusion follows necessarily from the premises.
A conclusion reached by this process.

usage For deduction

The logical processes known as deduction and induction work in opposite ways. In deduction general principles are applied to specific instances. Thus, using a mathematical formula to figure the volume of air that can be contained in a gymnasium is applying deduction. Similarly, applying a law of physics to predict the outcome of an experiment is reasoning by deduction. By contrast, induction makes generalizations based on a number of specific instances. The observation of hundreds of examples in which a certain chemical kills plants might prompt the inductive conclusion that the chemical is toxic to all plants. Inductive generalizations are often revised as more examples are studied and more facts are known. If certain plants that have not been tested turn out to be unaffected by the chemical, the conclusion about the chemical's toxicity must be revised or restricted. In this way, an inductive generalization is much like a hypothesis.

Cultural definitions for deduction (1 of 2)

deduction

A process of reasoning that moves from the general to the specific. (Compare induction.)

deduction

A cost or expense subtracted from revenue, usually for tax purposes.

Browse