reduce vs weaken

reduce and weaken both are verbs.

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

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

reduce (verb)	weaken (verb)
take off weight	become weaker
cut down on; make a reduction in	lessen the strength of
narrow or limit	reduce the level or intensity or size or scope of
cook until very little liquid is left	lessen in force or effect
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	destroy property or hinder normal operations
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