Each, however, is better than steak smothered in onions or potatoes fried in lard; any hygienist will tell you that.
But Aunt Plessington had made him a Haigite, which is one of the fiercer kinds of hygienist, just in the nick of time.
1844, "an expert on cleanliness," from hygiene + -ist. Earlier was hygeist (1716). Dental sense is recorded by 1913.