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 best rocks are hard, non-porous rocks with a non-gritty surface, ideally a seven on the Mohs’ hardness scale. — Bestreviews, Mercury News, 5 Aug. 2026

The porous pass rush, poor safety play and exploitable linebacking corps share some of the blame, but the cornerbacks didn’t do Washington any favors. — Tashan Reed, Washington Post, 4 Aug. 2026

These porous lattice designs consist of repeating three-dimensional networks that provide an ideal balance of stiffness, flexibility, and energy absorption. — Jijo Malayil, Interesting Engineering, 3 Aug. 2026

Apply enough of the product to treat the affected area, especially if the mess has soaked into the carpet or other porous material. — Caroline Lubinsky, Martha Stewart, 3 Aug. 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