overthrow vs overrule

overthrow is a noun but overrule is not a noun.

Word	Noun	Adjective	Verb	Adverb
overthrow	Yes	No	Yes	No
overrule	No	No	Yes	No

As verbs, overthrow and overrule are synonyms defined as:

Other synonyms of overthrow include override, overturn, reverse.

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

overthrow (verb)	overrule (verb)
rule against	rule against
cause the downfall of; of rulers