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.
(logic) A process of reasoning that moves from the general to the specific, in which a conclusion follows necessarily from the premises presented, so that the conclusion cannot be false if the premises are true.
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.