# Triskaideka vs. Dekatreís

**URL:** <https://boards.straightdope.com/t/triskaideka-vs-dekatreis/712570>\
**Category:** Factual Questions\
**Created:** [February 13, 2015, 2:20pm UTC](https://boards.straightdope.com/t/triskaideka-vs-dekatreis/712570 "2015-02-13T14:20:29Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![bienville](https://avatars.discourse-cdn.com/v4/letter/b/4bbf92/32.png) [@bienville](https://boards.straightdope.com/u/bienville)\
**Post date:** [February 13, 2015, 2:20pm UTC](https://boards.straightdope.com/t/triskaideka-vs-dekatreis/712570/1 "2015-02-13T14:20:29Z")

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**Triskaidekaphobia** is the fear of the number 13.

> [@](#):
>
> [From Greek](http://en.wikipedia.org/wiki/Triskaidekaphobia) tris meaning “3”, kai meaning “and”, deka meaning “10” and phobos meaning “fear”

**Paraskevidekatriaphobia** is the fear of Friday the 13th.

> [@](#):
>
> [From Greek](http://en.wikipedia.org/wiki/Friday_the_13th) Paraskeví (Παρασκευή, meaning “Friday”), and dekatreís (δεκατρείς, meaning “thirteen”).[

Why isn’t the fear of Friday the 13th “Paraskevitriskaidekaphobia”?

What determines the appropriateness of “Triskaideka” vs. “Dekatreís”?

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**Author:** ![Quartz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quartz/32/267_2.png) [@Quartz](https://boards.straightdope.com/u/Quartz)\
**Post date:** [February 13, 2015, 5:05pm UTC](https://boards.straightdope.com/t/triskaideka-vs-dekatreis/712570/2 "2015-02-13T17:05:20Z")

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Is the latter modern Greek? Vs Classical Greek for the former.

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**Author:** ![Apollon](https://avatars.discourse-cdn.com/v4/letter/a/e47774/32.png) [@Apollon](https://boards.straightdope.com/u/Apollon)\
**Post date:** [February 13, 2015, 6:09pm UTC](https://boards.straightdope.com/t/triskaideka-vs-dekatreis/712570/3 "2015-02-13T18:09:20Z")

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> [@Quartz](#):
>
> Is the latter modern Greek? Vs Classical Greek for the former.

Yes.  
Endeka (11) stayed endeka throughout history.  
Dodeka (12) stayed dodeka.  
Everything after 13 switched around when classical Greek evolved into modern Greek: triskaideka (13) became dekatreis; tetrakaideka (14) became dekatessera, etc.

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**Author:** ![running\_coach](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/running_coach/32/15836_2.png) [@running\_coach](https://boards.straightdope.com/u/running_coach)\
**Post date:** [February 13, 2015, 6:50pm UTC](https://boards.straightdope.com/t/triskaideka-vs-dekatreis/712570/4 "2015-02-13T18:50:39Z")

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For those so afflicted, would a 12-step program be advised?