Synonyms for Puritan (same or very similar meaning)
WordNet sense 1 (a person excessively concerned about propriety and decorum):
prudeWordNet sense 2 (morally rigorous and strict):
blue, puritanical, puritanicWordNet sense 3 (characterized by strictness, severity, or restraint):
strict, nonindulgentFrom the ODE community, based on WordNetadd/edit