Conformist

a person who conforms, esp. unquestioningly, to the usual practices or standards of a group, society, etc.

( often initial capital letter ) a person who conforms to the usages of an established church, esp. the Church of England.

of or characterized by conforming, esp. in action or appearance.

noun

babbit , bourgeois , brick in a wall , conventionalist , emulator , follower , one of the herd , rubber stamp * , sheep * , traditionalist , yes man

adjective

button-down , establishmentarian , orthodox , straight , traditional