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

Both teams sport inconsistent defenses that have been, at times, porous, while both Allen and Burrow hold upper-echelon passing abilities. —Jacob Camenker, USA Today, 7 Dec. 2025

Concrete is heavy, porous, and prone to chipping and etching. —Tessa Cooper, Southern Living, 7 Dec. 2025

However, their defense has been somewhat porous at times, which could be a concern when facing elite offensive pressure. —Ben Verbrugge, MSNBC Newsweek, 6 Dec. 2025

The pizza dough was so fluffy and porous on the inside, almost like focaccia. —Miguel Otárola, Denver Post, 4 Dec. 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