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

The innermost layer is a porous carbon buffer that absorbs recoil energy from fission fragments and provides internal clearance to collect gaseous fission products. — Aman Tripathi, Interesting Engineering, 23 July 2026

The porous textile allowed the electrode to stretch beyond 150% of its original size without breaking. — Kurt Knutsson, FOXNews.com, 21 July 2026

Shot in 2022 but set in the 1970s, the warmth of Mei’s projector light contrasts with the white LED lights from passing cars, a temporally porous mise-en-scène that Warnick exploits throughout his film. — Dylan Adamson, IndieWire, 21 July 2026

Like my favorite all-wheat pastas, it’s made in Italy and bronze-cut, which means each noodle is extruded through a bronze mold to create a textured, porous surface that’s especially great at clinging onto sauce. — Alaina Chou, Bon Appetit Magazine, 21 July 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