pervious

Pervious describes something that allows liquid, air, or other substances to pass through it. It is the opposite of impervious. The word is most often used for physical materials, surfaces, and natural ground that let water move through instead of blocking it. For example: "The pervious pavement allowed rainwater to seep into the ground, reducing runoff."

Think of a forest floor covered with leaves and soft soil: it is quite pervious, so water can reach the roots of trees. By contrast, traditional asphalt is not pervious; it keeps water from soaking in. The word is also used in geology and engineering for soil, rock, concrete, and other materials that allow water to flow through them.

Beyond physical materials, pervious can sometimes be used figuratively. In that sense, it means open to influence, change, or outside force. For example, a person might be described as pervious to suggestion, or a group might be pervious to outside pressure. This use is less common, but it keeps the same basic idea of something letting something else pass in.

So, whether you are talking about the ground under your feet, the materials used in construction, or a person being open to influence, pervious describes something that lets something pass through or enter.