overthrow vs bring down

overthrow is a noun but bring down is not a noun.

Word	Noun	Adjective	Verb	Adverb
overthrow	Yes	No	Yes	No
bring down	No	No	Yes	No

As verbs, overthrow and bring down are synonyms defined as:

Other synonyms of overthrow include overturn, subvert.

overthrow (noun)	bring down (noun)
the termination of a ruler or institution (especially by force)
the act of disturbing the mind or body

overthrow (verb)	bring down (verb)
rule against	cut down on; make a reduction in
cause the downfall of; of rulers	impose something unpleasant
	cause to be enthusiastic
	cause to come to the ground
	move something or somebody to a lower position
	cause the downfall of; of rulers