(1):

(superl.) Converting into stone; petrifying; petrific.

(2):

(superl.) Inflexible; cruel; unrelenting; pitiless; obdurate; perverse; cold; morally hard; appearing as if petrified; as, a stony heart; a stony gaze.

(3):

(superl.) Of or pertaining to stone, consisting of, or abounding in, stone or stones; resembling stone; hard; as, a stony tower; a stony cave; stony ground; a stony crust.