Noun
cold iron (uncountable)
Alternative form of cold steel (“swords, knives, bladed weapons”)
A teacher who is attempting to teach without inspiring the pupil with a desire to learn is hammering on cold iron. Horace Mann
Men of the eleventh! the enemy say we are good at a long shot, but cannot stand the cold iron. I call on you to give the lie to that slander. Charge! Winfield Scott
Stone walls confine a tinker; cold iron binds a witch; but a musician's music can never be fettered, for it lives first in her heart and mind. Charles de Lint
Will looking after her, sighed. not for her, he said under his breath, though there was no one to hear him, for me.... And he leaned his head against the cold iron gate. Cassandra Clare
Our real work is prayer. What good is the cold iron of our frantic little efforts unless first we heat it in the furnace of our prayer? Only heat will diffuse heat. Mother Maribel
You are striking cold iron. Arabic Proverb