po·​rous | \ ˈpȯr-əs How to pronounce porous (audio) \

Definition of porous

1a : possessing or full of pores
b : containing vessels hardwood is porous
2a : permeable to fluids
b : permeable to outside influences
3 : capable of being penetrated porous national boundaries

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Other Words from porous

porously adverb
porousness noun

Examples of porous in a Sentence

The country has a porous border. a cleaner that should not be used on porous surfaces

Recent Examples on the Web

The Chiefs went through a wholesale overhaul of their porous defense over the offseason, hiring a new coordinator, new assistants and bringing in eight new starters — give or take. Dave Skretta, The Denver Post, "Chiefs could be flying high again with offensive continuity," 7 Aug. 2019 But even setting the porous defense aside, FC Cincinnati is hurting for offensive firepower by any measure. Pat Brennan, Cincinnati.com, "FC Cincinnati's offense: Why can't they score more?," 23 July 2019 Payton’s problems are his 3-point shot (30% for career) and porous defense at the point of attack. Stefan Bondy, courant.com, "Who runs New York? The Top 25 players from the Nets and Knicks, ranked," 16 July 2019 However, their porous interior defense seemed to get worse as the season progressed. Rick Bonnell, charlotteobserver, "Charlotte Hornets have a rim-protection problem; will they draft a shot-blocker?," 4 June 2019 Borders in the region are porous, and people often take unofficial paths to visit neighboring nations. Washington Post, "World Digest: Aug. 7, 2019," 7 Aug. 2019 Everything is pliable, porous, and Porter’s typographical treats—alongside his turns with sound, repetition, and rhythm—exhibit his irrepressible sense of play. Maya Phillips, The New Yorker, "“Lanny” Is a Dark, Wonderfully Tactile Reimagining of the Folktale," 18 July 2019 The team landed on silica aerogel, a 97 percent porous material that allows light through but is an insulator that slows the conduction of heat. Jason Daley, Smithsonian, "This Material May Make Human Habitation on Mars Possible," 18 July 2019 Countertop materials like an engineered stone such as quartz are non-porous, resist stains and scratches, and do not require sealing. May Delgado, Houston Chronicle, "GHBA Remodelers Council: Experience low-maintenance living," 16 June 2019

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

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First Known Use of porous

14th century, in the meaning defined at sense 1a

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Statistics for porous

Last Updated

7 Sep 2019

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Time Traveler for porous

The first known use of porous was in the 14th century

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More Definitions for porous



English Language Learners Definition of porous

: having small holes that allow air or liquid to pass through
: easy to pass or get through


po·​rous | \ ˈpȯr-əs How to pronounce porous (audio) \

Kids Definition of porous

1 : full of small holes porous wood
2 : capable of absorbing liquids porous paper


po·​rous | \ ˈpōr-əs, ˈpȯr- How to pronounce porous (audio) \

Medical Definition of porous

1 : possessing or full of pores porous bones
2 : permeable to fluids

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More from Merriam-Webster on porous

Rhyming Dictionary: Words that rhyme with porous

Thesaurus: All synonyms and antonyms for porous

Spanish Central: Translation of porous

Nglish: Translation of porous for Spanish Speakers

Britannica English: Translation of porous for Arabic Speakers

Comments on porous

What made you want to look up porous? Please tell us where you read or heard it (including the quote, if possible).


concealment of treason or felony

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