• synonyms


[pawr-uhs, pohr-]
  1. full of pores.
  2. permeable by water, air, etc.
Show More

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


Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for porously

Contemporary Examples

British Dictionary definitions for porously


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

Word Origin

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 porously



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.

Show More
Online Etymology Dictionary, © 2010 Douglas Harper

porously in Medicine


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

porously in Science


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