1. The act of deducting.
2. That which is deducted; sum or amount taken from another; defalcation; abatement; as, this sum is a deduction from the yearly rent.
3. That which is drawn from premises; fact, opinion, or hypothesis, collected from principles or facts stated, or established data; inference; consequence drawn; conclusion; as, this opinion is a fair deduction from the principles you have advanced.