Definition

1. Adjective:
   • Made of cast iron: Describes an object or material that is formed from cast iron, a hard and brittle alloy of iron and carbon.
   • Extremely strong, robust, or unyielding: Used figuratively to describe something that is very strong, reliable, or inflexible, such as a person's will, a rule, or an argument.

Usage Examples

• Adjective (Literal - Made of cast iron):

  • The antique stove had a cast-iron frame.
  • Cast-iron pans are known for their excellent heat retention.

• Adjective (Figurative - Extremely strong/rigid):

  • She has a cast-iron will and never gives up.
  • He provided a cast-iron alibi for the night of the incident.
  • The company has a cast-iron rule about punctuality.

Advanced Usage

• "Cast-iron guarantee": An absolute, unquestionable guarantee.
  • The manufacturer offers a cast-iron guarantee on all its products for ten years.
• "Cast-iron stomach": An idiom describing someone who can eat anything without getting sick or upset.
  • You need a cast-iron stomach to eat that spicy food.

Variants and Related Words

• Cast iron (noun phrase): The material itself.
  • The bridge's supports were made of cast iron.
• Cast-iron (hyphenated adjective): The standard adjectival form, as defined above.

Synonyms

• Ironclad: Very certain or impossible to change or argue against (e.g., an ironclad contract).
• Unbreakable: Impossible to break or very strong.
• Adamantine: (Literary) Unbreakable; inflexibly strong.

Related Idioms

• "Cast-iron stomach": As mentioned in Advanced Usage.
• "Have nerves of steel / cast iron": To be very brave and not easily frightened.
  • A surgeon needs to have nerves of cast iron.

Adjective

1. extremely robust
   • an iron constitution