1
: having small holes that allow air or liquid to pass through
porous rock
a porous membrane/surface
2
: easy to pass or get through
The country has a porous border.
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“Porous.” Merriam-Webster.com Simple Definition, Merriam-Webster, https://www.merriam-webster.com/simple/porous. Accessed 21 Jun. 2026.
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