Nouns

(n)conservative, conservativista person who is reluctant to accept changes and new ideas

Adjectives

(a)conservativeresistant to change, particularly in relation to politics or religion
(s)conservativehaving social or political views favoring conservatism
(s)cautious, conservativeavoiding excess“a conservative estimate”
(s)button-down, buttoned-down, conservativeunimaginatively conventional“a colorful character in the buttoned-down, dull-grey world of business” (Newsweek)
(s)bourgeois, conservative, materialisticconforming to the standards and conventions of the middle class“a bourgeois mentality”