adjective
- made of cast iron.
- not subject to change or exception: a cast-iron rule.
- hardy: a cast-iron stomach.
noun
- an alloy of iron, carbon, and other elements, cast as a soft and strong, or as a hard and brittle, iron, depending on the mixture and methods of molding.
noun
- iron containing so much carbon (1.7 to 4.5 per cent) that it cannot be wrought and must be cast into shape
adjective cast-iron
- made of cast iron
- rigid, strong, or unyieldinga cast-iron decision
1660s, from cast (past participle adjective) “made by melting and being left to harden in a mold” (1530s), from past participle of cast (v.) in sense “to throw something in a particular way” (c.1300), especially “form metal into a shape by pouring it molten” (1510s). From 1690s as an adjective, cast-iron.