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

Removing Stains From Bathroom Floors Grout is porous and absorbs all the moisture, dirt, and soap scum it's exposed to, and that can leave it looking dark and dingy. —Karen Brewer Grossman, Southern Living, 28 Jan. 2026

Known for their exceptional thermal insulation, aerogels predominantly consist of air trapped within a porous solid matrix. —Georgina Jedikovska, Interesting Engineering, 26 Jan. 2026

The porous volcanic ash, known as picón, traps condensation from morning dew and slowly channels moisture toward the roots. —Emily Price, Forbes.com, 24 Jan. 2026

Its porous mesh walls offer both comfort and a thrilling proximity to the wild. —Condé Nast Traveler, 22 Jan. 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