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

Remember that porous planters and hanging baskets will dry out more quickly than plastic or glazed pots. — Mary Marlowe Leverette, Southern Living, 20 June 2026

Its specific surface area increased dramatically, creating a highly porous carbon product. — Aamir Khollam, Interesting Engineering, 19 June 2026

Mount Vesuvius’ eruption blanketed Pompeii and nearby Herculaneum in ash and pumice (a porous volcanic glass), preserving the infamous tragedy and its victims in astounding detail. — Margherita Bassi, Popular Science, 18 June 2026

That nuanced scale reveals more about a meteoroid's composition, which may range from dense, iron-rich material originating mostly from asteroids, to more fragile, porous debris that often sheds from a comet. — Eric Lagatta, USA Today, 17 June 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