Meaning of “deduction” - Learner’s Dictionary

deduction

noun [ C, U ] uk us /dɪˈdʌkʃən/
AMOUNT

the act of taking an amount away from a total, or the amount that is taken:

tax deductions
FACT

the process of deciding that something is true using the available information

(Definition of “deduction” from the Cambridge Learner’s Dictionary © Cambridge University Press)