Noah Webster
Indurate
IN'DURATE, verb intransitive [Latin induro; in and duro, to harden.]
To grow hard; to harden or become hard. Clay indurates by drying, and by extreme heat.
IN'DURATE, verb transitive To make hard. Extreme heat indurates clay. Some fossils are indurated by exposure to the air.
1. To make unfeeling; to deprive of sensibility; to render obdurate; as, to indurate the heart.