- the quality of being insensitive, indifferent, or unsympathetic; hardness of heart:Cutting off the unemployed from their benefits is a sad blend of callousness—a complete lack of empathy for the unfortunate—and unsound economics.
- a hardened or thickened condition of the skin or other tissue:Razors and shaving cause a callousness of the skin, which will encourage heavier hair growth and irritation.
