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 of porous

• 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

Tannins can also seep deep into porous concrete, making the stains difficult to wash away. — Brandee Gruener, Southern Living, 23 Oct. 2026

Sloan’s stylistic range reflects a music industry in which the borders between genres have never been more porous. — Mikael Wood, Los Angeles Times, 19 Oct. 2026

But the expansion of Bioko's strategy presents formidable challenges, from porous international borders to the sheer scale of the territory. — ABC News, 18 Oct. 2026

Engineers have tried to contain them in porous supports or seal them in capsules, but these fixes usually limit the salt to under 70% of the material, and encapsulation complicates manufacturing. — New Atlas, 18 Oct. 2026

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