Pronunciation: (di-duk'shun),[key] —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).