step-down vs reduction

step-down and reduction both are nouns.

Word	Noun	Adjective	Verb	Adverb
step-down	Yes	No	No	No
reduction	Yes	No	No	No

As nouns, step-down and reduction are synonyms defined as:

Other synonyms of step-down include decrease, diminution.

step-down (noun)	reduction (noun)
the act of decreasing or reducing something	the act of decreasing or reducing something
	the act of reducing complexity
	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