De*duc"tion (?), n. [L. deductio: cf. F. déduction.] 1. 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.

2. Act of deducting or taking away; subtraction; as, the deduction of the subtrahend from the minuend.

3. 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.

4. That which is deducted; the part taken away; abatement; as, a deduction from the yearly rent.

Syn. -- See Induction.

• that which is deducted; that which is subtracted or removed
  
• a sum that can be removed from tax calculations; something that is written off
       You might want to donate the old junk and just take the deduction.
  
• a conclusion; that which is deduced, concluded or figured out
       He arrived at the deduction that the butler didn't do it.
  
• the ability or skill to deduce or figure out; the power of reason
       Through his powers of deduction, he realized that the plan would never work.
  
• (Logic)a. a process of reasoning that moves from the general to the specific, in which a conclusion follows neccessarily from the premises presented, so that the conclusion cannot be false if the premises are true.
       b. a conclusion reached by this process