(1):

(n.) Fig.: Hardness; callousness; obduracy.

(2):

(n.) That which is petrified; popularly, a body incrusted with stony matter; an incrustation.

(3):

(n.) The process of petrifying, or changing into stone; conversion of any organic matter (animal or vegetable) into stone, or a substance of stony hardness.

(4):

(n.) The state or condition of being petrified.