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
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 research team achieved a substantial performance improvement through a simple spray coating polytetrafluoroethylene (PTFE), widely known as Teflon, onto the porous transport layer (PTL), a vital component of water electrolyzers.
—
Prabhat Ranjan Mishra, Interesting Engineering, 14 Dec. 2025
Currently being developed by scientists at Saudi Arabia's King Abdullah University of Science and Technology (KAUST), the device features an array of tiny, porous, hollow microneedles on its underside.
—New Atlas, 12 Dec. 2025
The porous border allows the TTP and other militants to retreat and regroup, while local militias and drone strikes may further destabilize the region.
—Amir Daftari, MSNBC Newsweek, 11 Dec. 2025
Both teams sport inconsistent defenses that have been, at times, porous, while both Allen and Burrow hold upper-echelon passing abilities.
—Jacob Camenker, USA Today, 7 Dec. 2025
See All Example Sentences for porous
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Prabhat Ranjan Mishra, Interesting Engineering, 14 Dec. 2025
Currently being developed by scientists at Saudi Arabia's King Abdullah University of Science and Technology (KAUST), the device features an array of tiny, porous, hollow microneedles on its underside.
—New Atlas, 12 Dec. 2025
The porous border allows the TTP and other militants to retreat and regroup, while local militias and drone strikes may further destabilize the region.
—Amir Daftari, MSNBC Newsweek, 11 Dec. 2025
Both teams sport inconsistent defenses that have been, at times, porous, while both Allen and Burrow hold upper-echelon passing abilities.
—Jacob Camenker, USA Today, 7 Dec. 2025
See All Example Sentences for porous
Cite this Entry
“Porous.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/porous. Accessed 19 Dec. 2025.
Copy CitationKids Definition
porous
adjective
po·rous
ˈpōr-əs 
ˈpȯr-
1
: full of pores
2
: capable of absorbing liquids
Medical Definition
porous
adjective
po·rous
ˈpōr-əs, ˈpȯr-
1
: possessing or full of pores
porous bones
2
: permeable to fluids
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