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

Yet doubts remain over whether digging ditches along short stretches of Chile's more than 4,800 miles of porous borders will do much to curb the flow of migrants, drugs, or contraband. —John Bartlett, NPR, 23 May 2026

Asphalt can be installed at different thicknesses for different needs, and porous asphalt is becoming more popular. —Aya Diab, Fortune, 23 May 2026

The dripping water, filtered through the porous lava rock, was also used as drinking water. —Kathleen Wong, USA Today, 20 May 2026

Once the mixture cools and hardens, the resulting material is a highly uniform, porous metal foam. —Mrigakshi Dixit, Interesting Engineering, 19 May 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