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 Brick is porous and has to breathe. —Soo Kim, MSNBC Newsweek, 3 Sep. 2025

Cellulose nanocrystals in plants are stronger than carbon fiber, yet their strength is only realized in about one percent due to the porous structure needed for growth. —Georgina Jedikovska, Interesting Engineering, 2 Sep. 2025

Porcelain and ceramic tiles are easy to maintain with a basic cleaning routine, and some types like natural stone are porous and need to be sealed for protection from everyday use. —Karen Brewer Grossman, Southern Living, 1 Sep. 2025

This converted the material to porous graphene. —New Atlas, 30 Aug. 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