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

Incorporating the copper nitrate trihydrate and potassium hydroxide allowed the team to engineer a highly porous carbon framework that effectively encapsulated the synthetic dye chemicals in wastewater. — Jennifer Bringle, Footwear News, 2 Oct. 2026

The gates blocking it, and the security checkpoints along its flanks, will dramatically limit the public’s desire to enter, and change the tenor and experience of a space that should feel porous and inclusive. — Los Angeles Times, 1 Oct. 2026

South Korean research team has designed a dry thick-film cathode technology using porous graphitic carbon nitride as a cathode additive. — Mrigakshi Dixit, Interesting Engineering, 30 Sep. 2026

The resulting structure is light and porous, with good compressive strength. — New Atlas, 26 Sep. 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