Meaning

noun the act of decreasing or reducing something

noun any process in which electrons are added to an atom or ion (as by removing oxygen or adding hydrogen); always occurs accompanied by oxidation of the reducing agent

noun the act of reducing complexity

originFrom Middle English reduccion, a borrowing from Old French reducion, from Latin reductiō, reductiōnem. Equivalent to reduce + -tion.

Etymology from Wiktionary, CC BY-SA 3.0