Webster's Revised Unabridged Dictionary · 1913

Induration

Induration , noun

[Compare French induration, Latin induratio hardness of heart.]

1.
The act of hardening, or the process of growing hard.
2.
State of being indurated, or of having become hard.
3.
Hardness of character, manner, sensibility, etc.; obduracy; stiffness; lack of pliancy or feeling.
A certain induration of character had arisen from long habits of business. — Coleridge