sanctimonious (adj) – making a hypocritical show of piety, devotion, or moral superiority; displaying a “holier-than-thou” attitude
BREAKDOWN: SANCT- (sacred or holy) + -MONY (status or behavior) + -OUS (full of)
— sanctimony is false or affected piety or righteousness
This word is built on the root SANCT-, which means sacred or holy.
Common SANCT- words include include saint and sanctuary.
More esoteric SANCT- words include sanctificate, sanctity, and sanctiloquence.