conservative vs button-down

conservative is a noun but button-down is not a noun.

Word	Noun	Adjective	Verb	Adverb
conservative	Yes	Yes	No	No
button-down	No	Yes	No	No

As adjectives, conservative and button-down are synonyms defined as:

Other synonyms of conservative include buttoned-down.

conservative (noun)	button-down (noun)
a person who is reluctant to accept changes and new ideas

conservative (adjective)	button-down (adjective)
resistant to change, particularly in relation to politics or religion	of a shirt; having the ends of the collar fastened down by buttons
unimaginatively conventional	unimaginatively conventional
conforming to the standards and conventions of the middle class
avoiding excess
having social or political views favoring conservatism