hy·gien·ist \(ˈ)hī|jēnə̇st, (ˈ)hī|jen-, also |hījē|en- or ˈhījə̇n-\noun (-s) Etymology: International Scientific Vocabulary hygiene + -ist : a specialist in hygiene; especially: one skilled in a specified branch of hygiene < dental hygienist > < mental hygienist >