superstition
nounUK /ˌsuːpəˈstɪʃən/
US /ˌsuːpərˈstɪʃən/
A belief that something magic or lucky will happen, even though it is not true.
It is just a superstition that black cats bring bad luck.
OTHER MEANINGS
2. A widely held but false idea about how something works.
It is a superstition that you catch a cold by going outside with wet hair.
3. A custom or action people do because they believe it brings good luck.
Knocking on wood is a common superstition.
4. An irrational fear or belief based on ignorance.
His superstition about the number thirteen made him avoid that room.