Triskaidekaphobia
(from Greek tris meaning "3", kai meaning "and", deka meaning "10" and phobos meaning "fear" or "morbid fear") is fear of the number 13 and avoidance to use it; it is a superstition and related to a specific fear of Friday the 13th, called paraskevidekatriaphobia (from Παρασκευή Paraskevi, Greek for Friday) or friggatriskaidekaphobia (after Frigg, the Norse goddess Friday is named after in English). (source: http://en.wikipedia.org/wiki/Triskaidekaphobia)
This means that if you see a word with "phobia" on a test, you know right away that it is a fear of something. For example: Ailurophobia is a fear of cats and Cynophobia is a fear of dogs. I'm a big Doctor Who fan (BBC TV show), so I like the word Anachrophobia, which is a fear of temporal displacement. That word was made up recently by an author (after all, Shakespeare made up words too), but it likely comes from "anachronism" mixed with "phobia."
Anachronism: something (such as a word, an object, or an event) that is mistakenly placed in a time where it does not belong in a story, movie, etc.: a person or a thing that seems to belong to the past and not to fit in the present
If you're a fan of Steampunk novels, you might already know "anachronism." Anachronism comes from Greek, with "chronos" meaning "time."
While I started with Friday the 13th, we found ourselves in Ancient Greece with time. I suppose the Ancient Greeks could have been pretty superstitious too.
