1620s, from Modern Latin rosa crucis (DuCange) or crux, Latinization of German Rosenkreuz, French rosecroix, from the secret society's reputed founder Christian Rosenkreuz, said to date from 1484, but not mentioned before 1614. As an adjective from 1660s.[Rosicrucian etymology, Rosicrucian origin, 英语词源]