noun which may take the genitive case particle 'no'
Technical term used in materials science, geology, and engineering to describe a substance containing many small holes or voids.
このフィルターは多孔質セラミックでできている。
This filter is made of porous ceramic.
porous material
Compound of 多 (many), 孔 (hole), and 質 (quality/substance). The exact historical derivation is uncertain, but the term is a modern technical coinage.