de·​duc·​tion | \ di-ˈdək-shən How to pronounce deduction (audio) , dē- \

Definition of deduction

1a : an act of taking away deduction of legitimate business expenses
b : something that is or may be subtracted deductions from his taxable income
2a : the deriving of a conclusion by reasoning based on intuition rather than deduction specifically : inference in which the conclusion about particulars follows necessarily from general or universal premises (see premise entry 1 sense 1) — compare induction
b : a conclusion reached by logical deduction made the deduction that the suspect had been at the scene of the crime

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Synonyms & Antonyms for deduction



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Frequently Asked Questions About deduction

What is the difference between deduction and induction?

Deductive reasoning, or deduction, is making an inference based on widely accepted facts or premises. If a beverage is defined as "drinkable through a straw," one could use deduction to determine soup to be a beverage. Inductive reasoning, or induction, is making an inference based on an observation, often of a sample. You can induce that the soup is tasty if you observe all of your friends consuming it. Read more on the difference between deduction and induction

What is the difference between abduction and deduction?

Abductive reasoning, or abduction, is making a probable conclusion from what you know. If you see an abandoned bowl of hot soup on the table, you can use abduction to conclude the owner of the soup is likely returning soon. Deductive reasoning, or deduction, is making an inference based on widely accepted facts or premises. If a meal is described as "eaten with a fork" you may use deduction to determine that it is solid food, rather than, say, a bowl of soup.

What is the difference between deduction and adduction?

Adduction is "the action of drawing (something, such as a limb) toward or past the median axis of the body," and "the bringing together of similar parts." Deduction may be "an act of taking away," or "something that is subtracted." Both words may be traced in part to the Latin dūcere, meaning "to lead."

Examples of deduction in a Sentence

The government is offering new tax deductions for small businesses. What is your pay after the deductions have been taken out? His guess was based on intuition rather than deduction. Our deduction was based on the information given to us at the time. It was a logical deduction.
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Recent Examples on the Web This deduction therefore has no economic justification. Douglas Carr, National Review, "How Lawmakers Could Respond to MLB’s Georgia Boycott," 11 May 2021 The deduction saved the company $800 million in 2019 and 2020 combined. Richard Rubin, WSJ, "Biden Tax Plan Takes Aim at Trump-Era Investment Incentive," 7 May 2021 This approach would ensure this valuable and proven tax deduction continues to yield the maximum aggregate energy savings it was designed to deliver by ensuring projects are both affordable and physically achievable. Julio Gonzalez, Forbes, "Why Lawmakers Should Adjust The New Energy Efficiency Deduction Standard," 16 Apr. 2021 For the vast majority of taxpayers that take the standard deduction instead of itemizing, the IRS is also offering tax relief., "Eligibility for vaccines rapidly expanding across US," 26 Mar. 2021 The majority of taxpayers take the standard deduction. Tribune News Service, oregonlive, "Think you’ll get a tax break for those work from home expenses? COVID-19 tax questions abound," 20 Feb. 2021 This is because the standard deduction was sharply increased, now reaching $12,400 for singles and $24,800 for couples. Rich Exner, cleveland, "Paying your entire property tax bill in December can mean tax savings: That’s Rich! short," 28 Dec. 2020 The new bill extends this deduction for 2021, and allows joint filers to deduct up to $600 next year. Kathleen Pender,, "New stimulus payments are coming to the Bay Area: Here’s what’s changed and what hasn’t," 22 Dec. 2020 The agent indicated that the money Andrew is accused of stealing allowed his interest rate deduction to go from 0.375% to 0.5%. Graham Kates, CBS News, "Charter school founder accused of stealing funds," 28 Apr. 2021

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'deduction.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of deduction

15th century, in the meaning defined at sense 1a

History and Etymology for deduction

see deduct

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Time Traveler for deduction

Time Traveler

The first known use of deduction was in the 15th century

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Statistics for deduction

Last Updated

15 May 2021

Cite this Entry

“Deduction.” Dictionary, Merriam-Webster, Accessed 15 May. 2021.

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More Definitions for deduction



English Language Learners Definition of deduction

: the act of taking away something (such as an amount of money) from a total
: something (such as an amount of money) that is or can be subtracted from a total
: the act or process of using logic or reason to form a conclusion or opinion about something : the act or process of deducing something


de·​duc·​tion | \ di-ˈdək-shən How to pronounce deduction (audio) \

Kids Definition of deduction

2 : an amount deducted
3 : a conclusion reached by reasoning Her deduction was based on all the clues.



Legal Definition of deduction

1 : an amount allowed by tax laws to be subtracted from income in order to decrease the amount of income tax due — see also Internal Revenue Code — compare credit, exclusion, exemption
business deduction
: a deduction usually taken from gross income that is allowed for losses or expenses attributable to business activities or to activities engaged in for profit
charitable deduction
: a deduction allowed for a contribution to a charity usually that is qualified under the tax law (as sections 170 and 2055 of the Internal Revenue Code)
dependency deduction
: a deduction allowed to be taken in a set amount for a qualified dependent (as under sections 151 and 152 of the Internal Revenue Code)
itemized deduction
: a deduction for a specifically recorded item that is allowed to be taken from adjusted gross income if the total of such deductions exceeds the standard deduction
marital deduction
1 : a deduction allowed under the Internal Revenue Code to be taken from the gross estate that amounts to the value of any property interest which is included in the estate and which was given by a decedent to the surviving spouse provided that the interest is not terminable during the life of the survivor
2 : a deduction allowed under the Internal Revenue Code of the value of any gift inter vivos subject to gift tax by one spouse to the other
personal deduction
: a deduction allowed to be taken for losses or expenses that are not necessarily attributable to a business activity or an activity engaged in for profit
personal exemption deduction
: a deduction for an amount set by tax law that under section 151 of the Internal Revenue Code includes the dependency deduction
standard deduction
: a deduction of an amount set by tax law that is allowed to be taken from adjusted gross income unless the taxpayer elects to itemize deductions
2 in the civil law of Louisiana : an item of property or an amount that an heir has a right to take from the mass of the succession before any of it is partitioned (as for a debt owed by the deceased to the heir)

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