Sanctimonious comes from Latin sanctimonia ('sacredness, holiness'), from sanctus ('holy') + -monia (abstract suffix); the pejorative sense of feigned piety developed in English by the 17th century. The historical chain includes Latin sanctimonia and Latin sanctus. Older glosses in the chain include "sacredness, holiness" and "holy", which help explain the semantic range of the modern word. Morphologically, sanctimonious is best read as compound, suffixal formation, and borrowing, yielding an English adjective shaped by both form history and later usage. In current English it functions as an adjective, with the sense "making a hypocritical show of moral or religious superiority". English derivatives include sanctimoniously and sanctimoniousness; related forms include sanctimony, sanctity, sanctify, and saint. The result is an English adjective whose etymology preserves the older forms while supporting the word's specialized modern meaning.