balker vs negativist

balker and negativist both are nouns.

Word	Noun	Adjective	Verb	Adverb
balker	Yes	No	No	No
negativist	Yes	No	No	No

As nouns, negativist is a hyponym of balker; that is, negativist is a word with a more specific, narrower meaning than balker:

balker: a person who refuses to comply
negativist: someone who refuses to do what is asked or does the opposite of what is asked

balker (noun)	negativist (noun)
a person who refuses to comply	someone who is resigned to defeat without offering positive suggestions
	someone who refuses to do what is asked or does the opposite of what is asked