iron-hearted

The Century Dictionary: The Encyelopedic Lexicon of the English Language · 1887 · p. 527

(i’érn-hiir’ted), a. Hard-hearted; unfeeling; cruel. These iron-hearted souldiers are so cold, Till they be beaten to a woman’s arms. Beau. and Fl., Laws of Candy, iv. 1. Think, ye masters iron-hearted, Lolling at your jovial boards. Cowper, Negro’s Complaint.