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
Grout, which is porous, can be a breeding ground for these unsightly and potentially hazardous issues.
—
Jamie Gold, Forbes, 5 Nov. 2024
Most fleeces are also porous enough to let breezes in, which is great for sweat mitigation but bad for comfort amidst 30-mph winds.
—Frederick Reimers, Outside Online, 31 Oct. 2024
This might sound excessive, but sponges are porous and hold onto food fragments and moisture.
—Katelyn Squiers, Better Homes & Gardens, 30 Oct. 2024
The gear’s 20 cubic cooling units are cut from a porous graphite that pulls water in; when wet, the units’ uneven surface increases the area from which moisture can evaporate, amplifying the body's natural cooling mechanism.
—Ashley Mateo, TIME, 30 Oct. 2024
See all Example Sentences for porous 
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Jamie Gold, Forbes, 5 Nov. 2024
Most fleeces are also porous enough to let breezes in, which is great for sweat mitigation but bad for comfort amidst 30-mph winds.
—Frederick Reimers, Outside Online, 31 Oct. 2024
This might sound excessive, but sponges are porous and hold onto food fragments and moisture.
—Katelyn Squiers, Better Homes & Gardens, 30 Oct. 2024
The gear’s 20 cubic cooling units are cut from a porous graphite that pulls water in; when wet, the units’ uneven surface increases the area from which moisture can evaporate, amplifying the body's natural cooling mechanism.
—Ashley Mateo, TIME, 30 Oct. 2024
See all Example Sentences for porous
Dictionary Entries Near porous
Cite this Entry
“Porous.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/porous. Accessed 17 Nov. 2024.
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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