from The American Heritage® Dictionary of the English Language, 4th Edition

  • n. The state or property of being porous.
  • n. A structure or part that is porous.
  • n. The ratio of the volume of all the pores in a material to the volume of the whole.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. The state of being porous
  • n. A measure of how porous a material is; the ratio of the volume of pores to the total volume

from the GNU version of the Collaborative International Dictionary of English

  • n. The quality or state of being porous; -- opposed to density.

from The Century Dictionary and Cyclopedia

  • n. The state or quality of being porose, porous, or pervious; perforation.
  • n. A pore or perforation.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • n. the property of being porous; being able to absorb fluids


from The American Heritage® Dictionary of the English Language, 4th Edition

Middle English porosite, from Old French, from Medieval Latin porōsitās, from porōsus, porous; see porous.


  • So we have the ability to measure what's called porosity, which is how big - how much wood volume as a whole, so how much stuff could there be and whether it's connected or not?

  • Windbreaks should have from 20-50% porosity, that is allow

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  • Before leaving the subject of local sandstones it will be necessary to refer to one quality they have which is of excellent utility as regards the storage of water, but which is decidedly a disadvantage in building stone -- that is, their porosity.

    The American Architect and Building News, Vol. 27, Jan-Mar, 1890

  • The gaps in the strands (also known as porosity) also cause hair to absorb moisture from the air like crazy -- explaining why many of us turn into Bozo the Clown on a rainy day.


  • The rock had an amazing 30% porosity, meaning that, like a sponge, it had lots of holes for holding gas.

    XXI Energy Goes Deep Into the Gulf

  • “We felt that we wanted to maintain the kind of porosity that we get in the best parts of the city,” said architect Rafael Pelli, who designed the plan along with FxFowle.

    West Side Rail Yards Proposal No. 2: Durst-Vornado Floats, Moves, Relocates People

  • Nitrogen fixing trees can improve soil physical properties, such as porosity and bulk density, and increase soil nutrient availability.

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  • But the awards if the sand package continues and has these big, thick high-pressured sands that had the kind of porosity and permeability we had at JB Mountain and Flatrock, which we expect them to be, as we said the flow rates of 50 to 100 million a day in 10 feet of water. Home Page

  • For one thing, to prevent a build-up of snow that can overwhelm the fence, they need a gap at the bottom equal to 10 percent of its height, and a "porosity," or amount of open area, of about 50 percent. local, state, business and sports news

  • Using only pen and paper, you take geological parameters such as porosity, temperature and pressure to calculate storage capacity, "Szulczewski said.

    Climate Ark Climate Change & Global Warming RSS Newsfeed


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  • that was illuminating, thank you! :-)

    September 15, 2008

  • I think porosity can always be used in place porousness, but not vice versa. One can say "a porosity in the surface marred the finish", which means that a particular area was flawed. But one would say "The porousness of the surface marred the finish", meaning that the whole surface was flawed.

    September 15, 2008

  • porosity/porousness. what are the differences in usage?

    September 15, 2008