Definition of porous in English:



  • 1(of a rock or other material) having minute interstices through which liquid or air may pass.

    ‘layers of porous limestones’
    ‘some rocks are more porous than others’
    • ‘Capillary action of the porous material pulls the ammonia borane into the pores of the support.’
    • ‘This drainage system is made up of a lower layer of rough, nonporous material and an upper layer of porous soil and sand.’
    • ‘Since drywall is a porous material, it can absorb melted paraffin when immersed in it.’
    • ‘The result is the formation of solid structures of a porous calcium carbonate rock also known as travertine.’
    • ‘Another is a rounded piece of clinker, a porous material that results from the burning of coal seams.’
    • ‘An aquifer is an underground bed of earth, gravel or porous stone that stores water.’
    • ‘You may even want to go over it with a primer if the material is porous.’
    • ‘We do very much the same sort of thing in reverse when we try to get oil out of porous rocks like sandstone and so on.’
    • ‘Coating a porous material like foam with this polymer makes it hydrophobic, so it won't absorb water.’
    • ‘It is by nature a very porous material and often cannot be completely restored.’
    • ‘They should not be used to vacuum porous materials, such as gypsum board.’
    • ‘The active oxygen and water vapour permeate through the porous rubber structure of the tyre over time, gradually reducing pressure.’
    • ‘The ion exchanger is porous and allows for a solution to permeate through the material.’
    • ‘A porous paper may absorb a lot of the ink and as a result, the colors may be lighter.’
    • ‘Braising in wine or a highly-seasoned stock allows porous mushrooms to absorb other flavors.’
    • ‘Moreover, they can also be seen as potential shape-selective catalysts by analogy with the porous minerals, zeolites.’
    • ‘A magnetic stir bar was placed in each chamber, separated from the root material by a porous metal screen.’
    • ‘Most masonry materials are porous and will absorb large amounts of water.’
    • ‘Most of the outer islands of the southern Tongass are made of limestone, a relatively soft, porous rock.’
    • ‘Mudstones are the main source of oil and gas, although by the time the oil or gas is extracted it has usually migrated to porous rocks such as sandstones of limestones.’
    permeable, penetrable, pervious
    absorbent, sponge-like, spongy, sieve-like, leaky, honeycombed, cellular, open, holey
    percolative, cavernulous, leachy, porose, poriferous, spongiose, foraminous, pory
    View synonyms
    1. 1.1Not retentive or secure.
      ‘he ran through a porous home defence to score easily’
      • ‘Is there tension between one of the league's perennially elite offenses and one of its most porous defenses?’
      • ‘Four veteran starters were signed as free agents to shore up the middle of the league's most porous defense.’
      • ‘Injuries and a porous defense were the main culprits in the collapse.’
      • ‘The porous defense is beginning to come under attack by the pitching staff.’
      • ‘He could not seem to hurt him, his defence was shockingly porous, and during most exchanges Sturm was a split-second ahead.’
      • ‘They won all the battles and and stiffened the defence which had been porous like in the first period.’
      • ‘Injuries and a porous defense that has the team playing catch-up have led to disappointment.’
      • ‘His stock also has been hurt by being shuffled around a lot on a porous defense.’
      • ‘The team will focus on fundamentals in an effort to improve its porous run defense.’
      • ‘Coming up next, how the man charged with this country's safety plans to secure our porous southern border.’
      • ‘Their defence has been porous since the start of the season but crucially it kept a clean sheet in the home victory over the Dutch last week.’
      • ‘The quick pace also has helped keep the porous defense more alert and involved.’
      • ‘This really shook the home side, whose own defence also looked a little on the porous side.’
      • ‘Their players are second to every ball, passes are going astray and their normally impenetrable defence is looking porous.’
      • ‘They'll be under, with a pretty porous defense and little help along the defensive line.’
      • ‘Not in the group stages of these two tournaments, however, did their defence appear so porous and their attack so unremarkable.’
      • ‘What that would tell Woodward was all about the porous defences rather than exhilarating attacks.’
      • ‘The captain's massive influence will be lost at a time when United's porous defence is allowing precious league points to leak away.’
      • ‘The Australians had clearly targeted him and he lost the ball frequently in the tackle and was porous in defence.’
      • ‘He chased down his own grubber to be the next man to take advantage of the porous Lancashire defence.’


Late Middle English: from Old French poreux, based on Latin porus pore.