From a Latin word meaning "consecrated" — saints and sanctions share the same root idea of making something untouchable.
A person recognized as holy or virtuous, especially one canonized by the Christian Church. Also used informally for any exceptionally good or patient person.
From Old French saint, seint, from Latin sanctus meaning 'holy, consecrated,' the past participle of sancire (to make sacred, to confirm by oath). The Latin root carried the sense of establishing something as inviolable. Key roots: *sak- (Proto-Indo-European: "to sanctify, to make a treaty"), sanctus (Latin: "holy, consecrated").
The word "saint" is a cousin of "sanction," and both come from the Latin idea of making something inviolable — consecrated and beyond tampering. Oddly, "sanction" evolved to mean both approval and punishment, while "saint" stayed firmly on the holy side. The abbreviation "St." in place names like St. Louis and