precisian

One who is strict and precise in adherence to established rules, forms, or standards, especially with regard to religious observance or moral behavior.

A Puritan.

Precise; punctiliously or ostentatiously observant of rules or doctrines.

Characteristic of precisians; puritanical.

One who adheres punctiliously to certain rules or observances; especially, one who is precise in matters of religion: often used depreciatingly with reference to the English Puritans of the seventeenth century.

One who limits, or restrains.

An overprecise person; one rigidly or ceremoniously exact in the observance of rules; a formalist; — formerly applied to the English Puritans.

A religious purist; a Puritan.

Someone who strictly observes the rules; a pedant or stickler.