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

• passable
• penetrable
• permeable
• pervious

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

Laminate isn’t porous, but moisture can still seep into seams and edges, causing peeling or swelling over time, according to Stein. —Daley Quinn, Southern Living, 7 Mar. 2025

But the front line was porous, with locals travelling back and forth to visit relatives, obtain medical care, and collect pensions. —Joshua Yaffa, The New Yorker, 24 Feb. 2025

West Ham have been porous defensively this season, conceding 46 goals in the Premier League. —Roshane Thomas, The Athletic, 7 Feb. 2025

The porous perimeter defense is something the Knicks can’t afford: The best teams in basketball — the ones New York will have to beat in the playoffs — live at the three-point line. —Kristian Winfield, New York Daily News, 21 Feb. 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