superstition

n. belief that is not based on fact; custom or action based on a superstitious belief; irrational fear of something that is unknown or mysterious

Superstition is a belief or notion, not based on reason or knowledge, in or of the ominous significance of a particular thing, circumstance, occurrence, proceeding, or the like.Superstition means one who overly stands, or not being progressive. As "new" religious beliefs and practices spread from one big city to another, people living in rural areas remained uninformed, continuing to practice as they had. Their beliefs were viewed as eccentric in the context of the cities. They were "superstitious" because they weren't doing what was new. Eventually the English word "superstition" came to imply a religion-like belief that stands outside the bounds of clerical religion.
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Noun
1. an irrational belief arising from ignorance or fear
(synonym) superstitious notion
(hypernym) belief

n. superstition, belief that is not based on fact, custom or action based on a superstitious belief; irrational fear of something that is unknown or mysterious

(n.)
The worship of a false god or gods; false religion; religious veneration for objects.
  

(n.)
Excessive nicety; scrupulous exactness.
  

(n.)
Belief in the direct agency of superior powers in certain extraordinary or singular events, or in magic, omens, prognostics, or the like.
  

(n.)
An ignorant or irrational worship of the Supreme Deity; excessive exactness or rigor in religious opinions or practice; extreme and unnecessary scruples in the observance of religious rites not commanded, or of points of minor importance; also, a rite or practice proceeding from excess of sculptures in religion.
  

(n.)
An excessive reverence for, or fear of, that which is unknown or mysterious.