[pawr-uhs, pohr-]


full of pores.
permeable by water, air, etc.

Origin of porous

1350–1400; Middle English, variant of porose < Medieval Latin porōsus. See pore2, -ous
Related formspo·rous·ly, adverbpo·rous·ness, nounnon·po·rous, adjectivenon·po·rous·ness, nounun·po·rous, adjectiveun·po·rous·ness, noun

Synonyms for porous

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Related Words for porous

penetrable, permeable, pervious, spongy, absorptive

Examples from the Web for porous

Contemporary Examples of porous

Historical Examples of porous

British Dictionary definitions for porous



permeable to water, air, or other fluids
biology geology having pores; poriferous
easy to cross or penetratethe porous border into Thailand; the most porous defence in the league
Derived Formsporously, adverbporousness, noun

Word Origin for porous

C14: from Medieval Latin porōsus, from Late Latin porus pore ²
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for porous

late 14c., "full of pores," from Old French poros (14c., Modern French poreux), from Medieval Latin porosus; or directly from Latin porus "an opening" (see pore (n.)). Figurative use from 1640s.

Online Etymology Dictionary, © 2010 Douglas Harper

porous in Medicine




Full of or having pores.
Admitting the passage of gas or liquid through pores.
Related formsporous•ness n.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

porous in Science



Having many pores or other small spaces that can hold a gas or liquid or allow it to pass through.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.