reduce vs replace

reduce and replace both are verbs.

Word	Noun	Adjective	Verb	Adverb
reduce	No	No	Yes	No
replace	No	No	Yes	No

As verbs, replace is a hypernym of reduce; that is, replace is a word with a broader meaning than reduce:

reduce: simplify the form of a mathematical equation of expression by substituting one term for another
replace: put in the place of another; switch seemingly equivalent items

Other hypernyms of reduce include exchange, interchange, substitute.

reduce (verb)	replace (verb)
take off weight	substitute a person or thing for (another that is broken or inefficient or lost or no longer working or yielding what is expected)
cut down on; make a reduction in	put something back where it belongs
narrow or limit	put in the place of another; switch seemingly equivalent items
cook until very little liquid is left	take the place or move into the position of
to remove oxygen from a compound, or cause to react with hydrogen or form a hydride, or to undergo an increase in the number of electrons
make smaller
reduce in size; reduce physically
make less complex
reduce in scope while retaining essential elements
lessen the strength or flavor of a solution or mixture
be cooked until very little liquid is left
be the essential element
destress and thus weaken a sound when pronouncing it
undergo meiosis
reposition (a broken bone after surgery) back to its normal site
lower in grade or rank or force somebody into an undignified situation
lessen and make more modest
simplify the form of a mathematical equation of expression by substituting one term for another
bring to humbler or weaker state or condition
put down by force or intimidation