New Delhi, Nov. 13 -- Would you cancel a trip because it falls on Friday the 13th? For some people, the date brings more than a passing worry. It can trigger intense fear even when there is no clear danger. That fear has a name that may be harder to face than the calendar itself. It is called paraskevidekatriaphobia.

The word comes from three Greek terms. Paraskevi means Friday, dekatria means thirteen, and phobia means fear. Another name for the same fear is friggatriskaidekaphobia. The fear of the number 13 alone is called triskaidekaphobia.

Say it slowly as par-uh-SKEE-vuh-dek-uh-TRY-uh-foh-bee-uh. Psychotherapist Donald Dossey helped popularise the term. He joked that once you could pronounce it, you were cured. Getting the syllable...