precisian

plural precisians

1. A religious purist; a Puritan.
2. Someone who strictly observes the rules; a pedant or stickler.

   “A sister of mine will be there,” explained the one, knowing the Duke to be a precisian.

   1911, Max Beerbohm, Zuleika Dobson

   1 more example

   Her speech was hardly more grating upon him, precisian though he was, than the careless, untutored lapses of a child might have been; all the senses of comparison as readily ignored them.

   1891, Mary Noailles Murfree, In the "Stranger Poeple's" Country, Nebraska, published 2005, page 47