1. subtraction, reduction, discount; conclusion; method of logical reasoning in which one uses a general rule to determine individual elements. deduction\de*duc"tion\ , n. [l. deductio: cf. f. déduction.].
2. act or process of deducing or inferring. the deduction of one language from another. this process, by which from two statements we deduce a third, is called deduction. r. seely.
3. act of deducting or taking away; subtraction; as, the deduction of the subtrahend from the minuend.
4. that which is deduced or drawn from premises by a process of reasoning; an inference; a conclusion. make fair deductions; see:
to what they mount.
5. that which is deducted; the part taken away; abatement; as, a deduction from the yearly rent.
6. Act or process of deducing or inferring.
7. Act of deducting or taking away; subtraction; as, the deduction of the subtrahend from the minuend.
8. That which is deduced or drawn from premises by a process of reasoning; an inference; a conclusion.
9. That which is deducted; the part taken away; abatement; as, a deduction from the yearly rent. reasoning from the general to the particular something that is inferred ; "his resignation had political implications" an amount or percentage deducted.
10. 1. A deduction is a conclusion that you have reached about something because of other things that you know to be true. It was a pretty astute deduction.
11. Deduction is the process of reaching a conclusion about something because of other things that you know to be true. a case that tested his powers of deduction.
12. A deduction is an amount that has been subtracted from a total. your gross income.
13. Deduction is the act or process of subtracting an amount of money from a total amount. After the deduction of tax at 20 per cent, the interest rate will be 6.2 per cent. In logic, a type of inference or argument that purports to be valid, where a valid argument is one whose conclusion must be true if its premises are true (see:
validity). Deduction is thus distinguished from induction, where there is no such presumption. Valid deductive arguments may have false premises, as demonstrated by the example: "All men are mortal; Cleopatra is a man; therefore, Cleopatra is mortal." Invalid deductive arguments sometimes embody formal fallacies (i.e., errors of reasoning based on the structure of the propositions in the argument); an example is "affirming the consequent": "If A then B; B; therefore, A" (see:
fallacy; formal and informal).