Superstition

Superstition was a belief system.

Before the Intuitive Revelation, Gallifrey was a matriarchal society ruled by the Pythia through magic and superstition. After the Revelation, it became patriarchal and promoted reason and science. (PROSE: Cat's Cradle: Time's Crucible)

People from the West Country were sometimes characterised as being traditional and somewhat superstitious. (PROSE: The Devil Goblins from Neptune)

The people of Sarn descended from a high-technology society into tribalism and superstition. They worshiped Logar, God of the Fire Mountain, and sacrificed unbelievers in fire. (TV: Planet of Fire)

The Architect was known to have been a Devotee of Apeiron though knowledge of this was kept secret amongst the Gallifreyans due to the superstition involved with being associated with such a cult at the time. (PROSE: The Ancestor Cell)

Friday the 13th was considered unlucky according to Rose Tyler. (COMIC: Triskaidekaphobia)