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

Keep one for meat and animal products, ideally made from a non-porous substance like metal, glass, or plastic. —Audrey Bruno, SELF, 10 Sep. 2025

The team from the Department of Chemical and Biological Engineering created CoFe-2DSA, a dual-metal single-atom catalyst made from cobalt and iron embedded in ultra-thin, porous carbon sheets. —Neetika Walter, Interesting Engineering, 10 Sep. 2025

Cleaning marble can be trickier than other popular countertop types because of the porous nature of this natural stone. —Patricia Shannon, Southern Living, 9 Sep. 2025

America is too porous, too open, too restless for permanent darkness. —John Hope Bryant, Time, 6 Sep. 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