triskaidekaphobia \tris-ky-dek-uh-FOH-bee-uh\, noun:
A morbid fear of the number 13 or the date Friday the 13th.
Thirteen people, pledged to eliminate triskaidekaphobia, fear of the number 13, today tried to reassure American sufferers by renting a 13 ft plot of land in Brooklyn for 13 cents . . . a month.
-- Daily Telegraph, January 14, 1967