go against vs buck

go against is not a noun while buck is a noun.

Word	Noun	Adjective	Verb	Adverb
go against	No	No	Yes	No
buck	Yes	No	Yes	No

As verbs, go against and buck are synonyms defined as:

go against (noun)	buck (noun)
	mature male of various mammals (especially deer or antelope)
	a framework for holding wood that is being sawed
	a gymnastic horse without pommels and with one end elongated; used lengthwise for vaulting
	a piece of paper money worth one dollar

go against (verb)	buck (verb)
act in disregard of laws, rules, contracts, or promises	jump vertically, with legs stiff and back arched
resist	move quickly and violently
fail to agree with; be in violation of; as of rules or patterns	resist
	to strive with determination