noun

penetration

pen-uh-TRAY-shuhn/ˌpenəˈtreɪʃn/

The act or extent of entering into or passing through something.

The cutaway shows water penetration below the soil's surface.

A small brown soil block shown in cutaway, with pale blue water poured from a plain watering-can spout into the top and visibly soaking down into the porous earth below the surface.

Etymology

The ending makes an action noun from “to put or get into.” English first used penetration for a puncture or piercing wound, then for the act of entering or piercing itself.

In context

GeoAtlas 2:29

This deep marine penetration creates a chaotic maze of coves, inlets, dynamic islands, and pristine natural harbors.

The Rhode Island Paradox: Why America’s Densest Corridor Has an Empty State

More examples

Cloudy water limits the penetration of sunlight.
Loose soil allows deeper root penetration.
The company measures its penetration into new markets.

Forms

penetration · penetrations

penetrate verb — To enter into or pass through something.

Similar words

entry: Entry means going in, without necessarily suggesting depth or passage through.
infiltration: Infiltration suggests gradual or concealed entry, often through small openings.
permeation: Permeation describes spreading throughout a substance, rather than simply entering.