- 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
- the conclusion of such an argument
- an argument of this type
Compare induction
WordReference Random House Learner's Dictionary of American English © 2026
de•duc•tion /dɪˈdʌkʃən/USA pronunciation
n.
WordReference Random House Unabridged Dictionary of American English © 2026-
- [uncountable] the act or process of deducting.
- [countable] something that is or may be deducted:a deduction of 10%.
-
- [uncountable] the act or process of inferring from known facts to a conclusion; the act or process of deducing:remarkable powers of deduction.
- [countable] something deduced from known facts:It was the detective's deduction that the robbery was an inside job.
- Philosophy
- [uncountable] a process of reasoning in which a conclusion must follow from the premises presented;
reasoning or concluding from the general to the particular or specific. - [countable] a conclusion reached by this process.
- [uncountable] a process of reasoning in which a conclusion must follow from the premises presented;
de•duc•tion
(di duk′shən),USA pronunciation n.
- 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.
- Philosophy[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. Cf. induction (def. 4).
- Latin dēductiōn- (stem of dēductiō) a leading away. See deduct, -ion
- Anglo-French)
- late Middle English deduccioun (1400–50
Collins Concise English Dictionary © HarperCollins Publishers::
deduction /dɪˈdʌkʃən/ n
'deduction' also found in these entries (note: many are not synonyms or translations):
clear
- consistent
- corollary
- deductive
- discount
- inference
- reason
- stoppage
- tare
- transcendental
- allowable
- allowance
- Aristotelianism
- capital
- checkoff
- conclusion
- deductible
- defalcation
- dockage
- geometry
- gross profit
- gross weight
- hypothetico-deductive method
- inconsequent
- logging
- money changing
- negative income
- net
- reprise
- tax deduction
- tret
- scalage
- sherlock