Triakaidekaphobia means “three, and, ten, fear” translated from the Greek words, meaning fear of 13.  Its a superstition and related to a specific fear of Friday the 13th, called paraskevidekatriaphobia, or translated from Greek meaning, “Friday, ten, three, fear”.  Many people believe that the number 13 is unlucky.

Some people also believe that Friday is an unlucky day.  The day may be unlucky because Christ died on Friday. According to the Bible, Adam and Eve were tempted by the serpent on a Friday, and the Great Flood of Noah’s time began on Friday. In some countries, Friday was the day for the execution of criminals.

Friday the 13th, has been considered an unlucky day since the 1800s, as a combination between an unlucky day, Friday, and the number 13.  Another theory as to why the date and number 13 is considered unlucky is that, on the day of Friday the 13th after the final Crusade the Pope had sent out men to capture and burn alive the last 13 Knights Templar in order to put an end to the Crusades.

Another theory states that the number 13 is unlucky because, once there were 13 full moons instead of 12, it made it difficult for the monks who were in charge of the calendars. This was considered a very unlucky circumstance, especially by the monks who were in charge of the calendars of thirteen months for that year, and it upset the normal arrangement of church festivals. For this reason thirteen came to be considered an unlucky number.

Here are some events that make us wonder about the number 13:

• The Bible tells us there were exactly 13 present at the Last Supper. One of the dinner guests, a disciple named Judas, betrayed Jesus Christ, setting the stage for the Crucifixion.
• If 13 people sit down to dinner together, one will die within the year.
• The Turks so disliked the number 13 that it was practically expunged from their vocabulary.
• Many cities do not have a 13th Street or a 13th Avenue.
• Many buildings don’t have a 13th floor.
• If you have 13 letters in your name, you will have the devil’s luck (Jack the Ripper, Charles Manson, Jeffrey Dahmer, Theodore Bundy, Albert De Salvo, Saddam Hussein, and Osama bin Laden). all have 13 letters in their names). 
• There are 13 witches in a coven.
• The Devil’s Dozen
• The apparitions of the Virgin of Fatima in 1917 were claimed to occur on the 13th of six consecutive months.
• 13 is the age that a Pagan or Wiccan usually starts to learn Witchcraft.
• Traditionally, there are 13 witches in a Wiccan coven.
• Believe it or not, many hotels don’t officially have a Room 13. Instead, the room is simply labeled as 12A or 12B
• Apollo 13 was the only unsuccessful mission by the U.S.A.’s NASA program to land a mission on the moon.

• In tarot cards, the number 13 is death.