overrule vs override

overrule is not a noun while override is a noun.

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

As verbs, overrule and override are synonyms defined as:

Other synonyms of overrule include overthrow, overturn, reverse.

overrule (noun)	override (noun)
	the act of nullifying; making null and void; counteracting or overriding the effect or force of something
	a manually operated device to correct the operation of an automatic device

overrule (verb)	override (verb)
rule against	rule against
	ride (a horse) too hard
	counteract the normal operation of (an automatic gear shift in a vehicle)
	prevail over