porous

adjective

po·​rous ˈpȯr-əs How to pronounce porous (audio)
Synonyms of porous
1
a
: possessing or full of pores
b
: containing vessels
hardwood is porous
2
a
: permeable to fluids
b
: permeable to outside influences
3
: capable of being penetrated
porous national boundaries
porously adverb
porousness noun

Synonyms of porous

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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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Removing Stains From Bathroom Floors Grout is porous and absorbs all the moisture, dirt, and soap scum it’s exposed to, and that can leave it looking dark and dingy. — Karen Brewer Grossman, Southern Living, 4 Sep. 2026 In addition, homeland defense against cruise missiles remains porous. — Seth G. Jones, Foreign Affairs, 3 Sep. 2026 Although West Ham remain porous defensively, the addition of Morato from Nottingham Forest should help strengthen their back line. — Roshane Thomas, New York Times, 3 Sep. 2026 Lynn replaced Alex Grinch, who was fired before finishing his second season leading a defense that was porous and poor, ranking as the 94th and 121st most generous defense in the nation in 2022 and ’23, respectively. — Mirjam Swanson, Los Angeles Times, 30 Aug. 2026 See All Example Sentences for porous

Word History

First Known Use

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

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

Phrases Containing porous

Rhymes for porous

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Browse Nearby Words

porosity
porous
porous cell
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Cite this Entry

“Porous.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/porous. Accessed 4 Sep. 2026.

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Kids Definition

porous

adjective
po·​rous ˈpōr-əs How to pronounce porous (audio)
ˈpȯr-
1
: full of pores
2
: capable of absorbing liquids

Medical Definition

porous

adjective
po·​rous ˈpōr-əs, ˈpȯr- How to pronounce porous (audio)
1
: possessing or full of pores
porous bones
2
: permeable to fluids
Last Updated: - Updated example sentences
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