The process of changing into stone; the conversion of wood or any animal or vegetable substance into stone or a body of stony hardness. When the water in which wood is lodged is slightly impregnated with petrescent particles, the petrifaction very slowly takes place.

That which is converted from animal or vegetable substance into stone. --The calcarious petrifaction called osteocolla. An organized body rendered hard by depositions of stony matter in its cavities.

In popular usage, a body incrusted with stony matter; an incrustation.