/di duk"sheuhn/ , n.
1. the act or process of deducting; subtraction.
2. something that is or may be deducted: She took deductions for a home office and other business expenses from her taxes.
3. the act or process of deducing.
4. something that is deduced: His astute deduction was worthy of Sherlock Holmes.
5. Logic.
a. 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.
b. a conclusion reached by this process. Cf. induction (def. 4).
[ 1400-50; late ME deduccioun ( deduction- (s. of deductio ) a leading away. See DEDUCT, -ION ]