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

While Caleb Williams shows promise and the offense boasts young talent, a porous defense and strong divisional rivals like the Lions, who have an easier schedule, present considerable hurdles to Johnson's lofty aspirations. — John Cassillo, Forbes.com, 12 Aug. 2026

Choose planters with proper drainage, suitable size, and porous materials to prevent waterlogging. — Lauren Landers, The Spruce, 10 Aug. 2026

Soil This succulent requires a porous, well-draining soil such as those containing sand, loam, rock, or grit. — Kim Toscano, Southern Living, 9 Aug. 2026

The only invention was a double-layered scrim system printed with two offset mesh layers with a more porous front layer and a denser one in the back separated by a one-foot air gap. — Lauren Sinclair, Curbed, 7 Aug. 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