If you suffer from this malady–the fear of Friday the 13th–you might want to read on, as you’re probably only succumbing to a recently minted superstition rather than one grounded in age-old mystic wisdom or scientific data…
As for the etymology of friggatriskaidekaphobia, Frigga is the name of the Norse goddess who is the wife of Oddin and after whom Friday is named. Her name is prefixed to the term triskaidekaphobia (fear of the number thirteen), which derives from an alteration of the Greek word dekatreís (thirteen) and the modern English phobia (from the Greek phóbos, fear). An alternate term for the fear of Friday the 13th is paraskevidekatriaphobia, employing the Greek word for Friday (Paraskeví) rather than the Norse-derived word.
But notwithstanding the daunting terminology, there’s probably very little about Friday the 13th warranting fear. There are seemingly no written accounts of this superstition predating the 19th century, when an obscure reference appears in an 1869 biography of Italian composer Gioachino Rossini written by British journalist Henry Sutherland Edwards. Theories about the origins of friggatriskaidekaphobia abound, however, one of which posits that it is merely a modern merging of two older superstitions about the number thirteen and Friday itself each being unlucky in its own right.
In numerology, twelve is considered a fine, upstanding and happy number–a number with such pleasing associations as the number of months of the year, hours of the clock, Christian Apostles, Olympian gods, tribes of Israel, Imams succeeding Muhammad, etc. In contrast, thirteen is a naughty number for its irregular transgression of twelve’s neat completeness. There is also a superstition that thirteen people sitting down at the same dinner table will lead to the death of one of the diners, perhaps deriving from the fact that Judas Iscariot (who later betrayed Jesus so as to lead to his crucifixion) was said to have been the thirteenth guest to sit down to the Last Supper. Even Gandalf knew the dwarves needed Bilbo Baggins to bump their party up to fourteen.
Turning to Friday, Christ’s crucifixion was said to have taken place on that particular day of the week. It was considered an unlucky day at least as far back as the 14th Century, as reflected in Chaucer’s Canterbury Tales. In the Nun’s Priest’s Tale (see an image of the priest, above, from the 15th-century Ellesmere manuscript), Chaucer alludes to Friday as being a day on which bad things seemed to occur, to wit:
O destinee, that mayst nat been eschewed!
Allas, that Chauntecleer fleigh fro the bemes!
Allas, his wyf ne roghte nat of dremes!
And on a Friday fil al this meschaunce.
— From the Nun’s Priest’s Tale, lines 572-575.
As it turns out, though, there’s no hard data to support the theory that Friday the 13th is a particularly unlucky Friday. It’s therefore probably not something any of us has to worry about. But just in case, if you find yourself breaking bread with twelve friends later today, maybe play it safe and avoid the salmon mousse…