thwarter vs stonewaller

thwarter and stonewaller both are nouns.

Word	Noun	Adjective	Verb	Adverb
thwarter	Yes	No	No	No
stonewaller	Yes	No	No	No

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

thwarter: someone who systematically obstructs some action that others want to take
stonewaller: one who stonewalls or refuses to answer or cooperate; someone who delays by lengthy speeches etc.

Other hyponyms of thwarter include naysayer.

thwarter (noun)	stonewaller (noun)
someone who systematically obstructs some action that others want to take	one who stonewalls or refuses to answer or cooperate; someone who delays by lengthy speeches etc.