tris·​kai·​deka·​pho·​bia ˌtri-ˌskī-ˌde-kə-ˈfō-bē-ə How to pronounce triskaidekaphobia (audio) ˌtri-skə- How to pronounce triskaidekaphobia (audio)
: fear of the number 13

Did you know?

It's impossible to say just how or when the number thirteen got its bad reputation. There are a number of theories, of course. Some say it comes from the Last Supper because Jesus was betrayed afterwards by one among the thirteen present. Others trace the source of the superstition back to ancient Hindu beliefs or Norse mythology. But if written references are any indication, the phenomenon isn't all that old (at least, not among English speakers). Known mention of fear of thirteen in print dates back only to the late 1800s. By circa 1911, however, it was prevalent enough to merit a name, which was formed by attaching the Greek word for "thirteen"—treiskaideka (dropping that first "e")—to phobia ("fear of").

Example Sentences

Recent Examples on the Web Get a grip on your triskaidekaphobia and revisit this seminal 1980 slasher flick about oversexed young camp counselors and the knife- and -ax-wielding homicidal maniac who hates them. Matt Cooperlistings Coordinator, Los Angeles Times, 12 May 2022 Whatever the reason, the number 13 is a real thing, so much so that it has been given its own name – triskaidekaphobia. Leada Gore |, al, 13 Sep. 2019 Friday is Friday the 13th, a day for all those suffering from triskaidekaphobia to beware! CBS News, 8 Sep. 2019 Is fear of this number, also known as triskaidekaphobia, merely silly superstition, or is it something more? Aliza Kelly Faragher, Allure, 29 Aug. 2018 The irrational fear of the number 13 is now called triskaidekaphobia. Lily Puckett, Teen Vogue, 12 July 2018 And many other airlines and airports avoid slapping the number 13 on aisles, flights and gates — sometimes out of logistics and other times because of triskaidekaphobia, according to the Wall Street Journal. Melissa Chan, Time, 13 Oct. 2017 Investors who suffer from triskaidekaphobia or paraskevidekatriaphobia might want to tread carefully when trading stocks on Friday the 13th. Adam Shell, USA TODAY, 13 Oct. 2017 On the top of her spelling list these days: triskaidekaphobia, fear of the number 13. Carli Teproff, miamiherald, 28 May 2017 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'triskaidekaphobia.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Word History


New Latin, from Greek treiskaideka thirteen (from treis three + kai and + deka ten) + New Latin phobia — more at three, ten

First Known Use

circa 1909, in the meaning defined above

Time Traveler
The first known use of triskaidekaphobia was circa 1909


Dictionary Entries Near triskaidekaphobia

Cite this Entry

“Triskaidekaphobia.” Dictionary, Merriam-Webster, Accessed 6 Feb. 2023.

Medical Definition


tris·​kai·​deka·​pho·​bia ˌtris-ˌkī-ˌdek-ə-ˈfō-bē-ə How to pronounce triskaidekaphobia (audio) ˌtris-kə- How to pronounce triskaidekaphobia (audio)
: fear of the number 13
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