noun

1. R.C.Ch. a committee of cardinals, the Congregation for the Propagation of the Faith, in charge of the foreign missions
2. any systematic, widespread dissemination or promotion of particular ideas, doctrines, practices, etc. to further one's own cause or to damage an opposing one
3. ideas, doctrines, or allegations so spread: now often used disparagingly to connote deception or distortion

Etymology: ModL, short for congregatio de propaganda fide, congregation for propagating the faith: see propagate