A morbid fear of the number 13

WordNet Word definitions in WordNet
n. a morbid fear of the number 13

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
"fear of the number 13," 1908, also triskaidecaphobia , from Greek treiskaideka , triskaideka "thirteen" (from treis "three" + deka "ten") + -phobia "fear."

Wiktionary Word definitions in Wiktionary
n. fear, hate, or dislike of the number thirteen (13).

Wikipedia Word definitions in Wikipedia
Triskaidekaphobia (, or ; from Greek tris meaning "three", kai meaning "and", deka meaning "10" and phobos meaning "fear" or "morbid fear") is fear of the number and avoidance to use it. It is also a reason for the fear of Friday the 13th , called paraskevidekatriaphobia ...