English Reference
noun

infiltration

n.
US /ˌɪnfɪɫˈtɹeɪʃən/ UK /ˌɪnfɪltɹˈeɪʃən/ in·fil·tra·tion UK spelling infiltrations

  1. 01 C2 Proficiency Technical Science

    the process of a liquid slowly passing into a solid material through small holes.

    the process by which a fluid passes into or through a porous substance or the interstices of a structure.

    Simple

    Heavy rain led to the infiltration of water into the basement through the old walls.

    In context

    The study measured the rate of water infiltration in different soil types to predict how quickly the ground would dry after a storm.

    Usage

    Often followed by the preposition 'of' for the substance and 'into' for the destination.

    seepagepercolationabsorption

Measures have been implemented to try to prevent jellyfish infiltration, including a partnership with fishermen who capture and release them further offshore, according to French outlet Ici.

BBC News· 27 Aug 2026

Infiltration often begins with a quiet search for access.

The Conversation· 4 Aug 2026

From Middle English infiltracioun, from Medieval Latin infiltrātiōnem, infiltrātiō. By surface analysis, infiltrat(e) + -ion.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Origin la-med infiltrātiōnem
Level C1 · Advanced
Frequency Frequent
Updated