porous
Americanadjective
-
full of pores.
-
permeable by water, air, etc.
- Synonyms:
- riddled, sievelike, pervious, penetrable
adjective
-
permeable to water, air, or other fluids
-
biology geology having pores; poriferous
-
easy to cross or penetrate
the porous border into Thailand
the most porous defence in the league
Other Word Forms
Etymology
Origin of porous
First recorded in 1350–1400; Middle English, variant of porose, from Medieval Latin porōsus; see pore 2, -ous
Explanation
If something is full of tiny holes or openings, you can describe it as porous. A sponge is porous, and if the border between countries is open for anyone to cross easily, it too can be called porous. You can see the word pore — meaning "a tiny opening" — in porous. When potters make a mug, they use special glazes to seal the porous clay, which otherwise would absorb the liquid you put in the mug. This meaning has expanded so porous can describe any barrier that allows easy passage in and out, like the porous border between two countries that allows residents to move easily between them.
Vocabulary lists containing porous
Can You Dig It? Words for Dirt and Soil
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"An Awful Human Trade," Vocabulary from the news article
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All Thirteen
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
Its porous architecture, combined with its ability to keep EV signals concentrated in the damaged region, appeared to be critical to the repair response.
From Science Daily ● Sep. 4, 2026
Pesticides prohibited in Kenya are sometimes smuggled across this porous border with Tanzania and used in farms within the Amboseli area, where elephants live near human settlements and are known to raid farms for food.
From BBC ● Aug. 24, 2026
A nanoscale hollow cavity is surrounded by a porous shell, forming a confined environment where reactants can accumulate.
From Science Daily ● Aug. 6, 2026
They brilliantly reveal Babitz’s eye for the deep shallow as well as explore the porous boundary between the largely self-inflicted injuries of her private life and the glittering sheen of her public persona.
From Los Angeles Times ● Jul. 27, 2026
Everything seemed greener, more porous, as though air could flow more freely than it had only yesterday.
From "What the Night Sings" by Vesper Stamper
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
