# inflammable, infamous, i don't get it

**URL:** <https://boards.straightdope.com/t/inflammable-infamous-i-dont-get-it/72593>\
**Category:** Factual Questions\
**Created:** [July 15, 2001, 5:46pm UTC](https://boards.straightdope.com/t/inflammable-infamous-i-dont-get-it/72593 "2001-07-15T17:46:17Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![influent](https://avatars.discourse-cdn.com/v4/letter/i/258eb7/32.png) [@influent](https://boards.straightdope.com/u/influent)\
**Post date:** [July 15, 2001, 5:46pm UTC](https://boards.straightdope.com/t/inflammable-infamous-i-dont-get-it/72593/1 "2001-07-15T17:46:17Z")

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Why do inflammable and infamous have somewhat counterintuitive meanings?

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**Author:** ![friedo](https://avatars.discourse-cdn.com/v4/letter/f/8edcca/32.png) [@friedo](https://boards.straightdope.com/u/friedo)\
**Post date:** [July 15, 2001, 5:56pm UTC](https://boards.straightdope.com/t/inflammable-infamous-i-dont-get-it/72593/2 "2001-07-15T17:56:08Z")

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“Infamous” is the adjective form of “infamy,” and is not related to “famous” as far as I know. Not sure about inflammable.

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**Author:** ![RealityChuck](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/realitychuck/32/195_2.png) [@RealityChuck](https://boards.straightdope.com/u/RealityChuck)\
**Post date:** [July 15, 2001, 7:06pm UTC](https://boards.straightdope.com/t/inflammable-infamous-i-dont-get-it/72593/3 "2001-07-15T19:06:36Z")

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in- as a prefix has several meanings. The most common is “not,” however other meanings include “inward,” “intensive action,” and “to cause.” Thus, “infamous” derives for “not” (originally, it meant “not famous”). “Inflammable” derives from “to intensify.” An inflammable liquid causes flames to intensify.

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**Author:** ![rowrrbazzle](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rowrrbazzle/32/414_2.png) [@rowrrbazzle](https://boards.straightdope.com/u/rowrrbazzle)\
**Post date:** [July 15, 2001, 9:06pm UTC](https://boards.straightdope.com/t/inflammable-infamous-i-dont-get-it/72593/4 "2001-07-15T21:06:45Z")

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As shown below, “famous” and “infamous” both ultimately derive from Latin “fama” via slightly different routes.

> **[Definition of FAMOUS](https://www.merriam-webster.com/dictionary/famous)**
>
> widely known; honored for achievement; excellent, first-rate… See the full definition

> [@](#):
>
> Main Entry: fa·mous  
> Etymology: Middle English, from Middle French fameux, from Latin famosus, from fama fame  
> Date: 14th century

[http://www.m-w.com/cgi-bin/dictionary?book=Dictionary&va=infamous](http://www.m-w.com/cgi-bin/dictionary?book=Dictionary&va=infamous)

> [@](#):
>
> Main Entry: in·fa·mous  
> Etymology: Middle English, from Latin infamis, from in- + fama fame  
> Date: 14th century

[http://www.m-w.com/cgi-bin/dictionary?book=Dictionary&va=infamy](http://www.m-w.com/cgi-bin/dictionary?book=Dictionary&va=infamy)

> [@](#):
>
> Main Entry: in·fa·my  
> Pronunciation: -mE  
> Function: noun  
> Inflected Form(s): plural -mies  
> Date: 15th century  
> 2 b : the state of being infamous