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

These coatings are typically lifetime-guaranteed to prevent stains from penetrating the porous surface, which can give you extra peace of mind. —Daley Quinn, Southern Living, 6 June 2026

Nationally, the crisis has often felt insurmountable, frequently exacerbated by porous borders and passive, hands-off approaches to addiction in many states. —John Koufos, Sun Sentinel, 2 June 2026

What Rocky understood early on was how porous culture was becoming. —Jeff Ihaza, VIBE.com, 2 June 2026

Germs often survive longer on smooth, nonporous materials like plastic, stainless steel, and glass than on porous surfaces, Ali says. —Caroline Lubinsky, Martha Stewart, 1 June 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