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

In recent years, West Africa has emerged as a key transit route for cocaine trafficked from South America to Europe, with smugglers taking advantage of porous borders and weak enforcement in parts of the region. — ABC News, 30 July 2026

In addition to bacterial growth, strong-smelling food residue can transfer odors to porous kitchen materials such as wood, fabrics, and sponges. — Olivia McIntosh, Martha Stewart, 27 July 2026

Researchers think the moon is blanketed by porous layers of volcanic ash, sulfur frost and other eruptive debris that continually resurface Io, burying older terrain beneath fresh deposits. — Samantha Mathewson, Space.com, 24 July 2026

The innermost layer is a porous carbon buffer that absorbs recoil energy from fission fragments and provides internal clearance to collect gaseous fission products. — Aman Tripathi, Interesting Engineering, 23 July 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