reactionary vs far-right

reactionary is a noun but far-right is not a noun.

Word	Noun	Adjective	Verb	Adverb
reactionary	Yes	Yes	No	No
far-right	No	Yes	No	No

As adjectives, reactionary and far-right are synonyms defined as:

reactionary and far-right: opposed to political or social liberalism or reform

Other synonyms of reactionary include reactionist.

reactionary (noun)	far-right (noun)
an extreme conservative; an opponent of progress or liberalism

reactionary (adjective)	far-right (adjective)
opposed to political or social liberalism or reform	opposed to political or social liberalism or reform