porous

adjective

po·​rous ˈpȯr-əs 

1

a

: possessing or full of pores

b

: containing vessels

hardwood is porous

2

a

: permeable to fluids

b

: permeable to outside influences

3

: capable of being penetrated

porous national boundaries

porously adverb

porousness noun

Synonyms

• penetrable
• permeable

Examples of porous in a Sentence

The country has a porous border.

a cleaner that should not be used on porous surfaces

Recent Examples on the Web

The process of seasoning involves heating up unsaturated fats, often high-heat oils like grape-seed oil or canola oil, atop a porous metal like carbon steel or cast iron. —Matthew Korfhage, Wired News, 6 Aug. 2025

My scrim between reality and memory, truth and simulation, had become porous, faulty. —Sophie Brickman, The Atlantic, 4 Aug. 2025

Stone surfaces, including marble, granite, and quartz, are porous and bleach can wreak havoc of these beautiful materials. —Lauren David, Southern Living, 30 July 2025

Desalination of seawater is a possible solution, and one approach involves porous materials absorbing water that evaporates when heated by solar energy. —Elizabeth Rayne, ArsTechnica, 26 July 2025

Word History

First Known Use

14th century, in the meaning defined at sense 1a

Phrases Containing porous

• diffuse-porous
• ring-porous

Rhymes for porous

• chloris
• chorus
• horus
• lores
• morrice
• morus
• orris
• porus
• torus
• authorise
• clitoris
• liquorice

Kids Definition

porous

adjective

po·​rous ˈpōr-əs 

ˈpȯr-

1

: full of pores

2

: capable of absorbing liquids

Medical Definition

porous

adjective

po·​rous ˈpōr-əs, ˈpȯr- 

1

: possessing or full of pores

porous bones

2

: permeable to fluids