the state or quality of not feeling or showing any emotion or sympathy, the quality of being hard-hearted and callous;
e.g. They were shocked by his callosity and lack of care for the feelings of others.
(noun)
(technical) the state or quality of being abnormally hardened or thickened, typically describing a part of the skin, or an instance of this (i.e. a callus);
e.g. She developed a callosity on the side of her foot.