Full of pores; having interstices in the skin or in the substance of the body; having spiracles or passages for fluids; permeable by liquids; as, a porous skin; porous wood.

containing pores, or holes that permit the movement of fluids or gases. An example of a porous material is a sponge. Porosity is the extent to which a substance contains pores. Swiss cheese has high porosity compared to cheddar.

having many pores.

Material that has openings through which liquid will pass in filtering. Also referred to as permeable or pervious.

This is where something allows water and air in easily. For example, paper is porous.

something which allows water to pass through it. Compare nonporous.

A porous material will allow water born and other contaminants to penetrate and should be sealed

The ability for paper to allow air to permeate and ink to penetrate. The more porous the paper, the higher the capability for ink penetration.

A coin with a rough or granular/pitted surface from oxidation.

Having a granular surface as the result of oxidation, most frequently found with older copper coins

slightly pitted due to cleaning or chemical action.

A rough surface on a coin caused by a planchet in poor condition. Also caused by burial or other prolonged contact with contaminants.