cast iron: meaning, definition, pronunciation and examples
B2Neutral; used in both informal and formal contexts, particularly in technical, industrial, and figurative language.
Quick answer
What does “cast iron” mean?
A hard, brittle alloy of iron, carbon, and silicon, shaped by pouring molten metal into a mould.
Audio
Pronunciation
Definition
Meaning and Definition
A hard, brittle alloy of iron, carbon, and silicon, shaped by pouring molten metal into a mould.
Describing something extremely strong, durable, unwavering, or certain. It can refer to a physical object, an argument, or a guarantee.
Dialectal Variation
British vs American Usage
Differences
Primarily spelling and phrasing in examples. British English may more commonly use the hyphenated adjectival form 'cast-iron'. The term is equally common and understood in both varieties.
Connotations
Identical in both varieties, connoting strength, reliability, and inflexibility.
Frequency
Similar frequency; common in industrial, culinary, and figurative contexts.
Grammar
How to Use “cast iron” in a Sentence
[be] made of cast iron[have] a cast-iron [noun]as strong as cast ironcast-iron [noun] (attributive adjective)Vocabulary
Collocations
Examples
Examples of “cast iron” in a Sentence
verb
British English
- The factory used to cast iron for Victorian railings.
- They will cast the iron into intricate moulds.
American English
- The company casts iron for engine blocks.
- We cast the iron in our own foundry.
adverb
British English
- Not typically used as an adverb.
American English
- Not typically used as an adverb.
adjective
British English
- She has a cast-iron constitution.
- The police confirmed his cast-iron alibi.
American English
- He cooked steak in his cast-iron skillet.
- We need a cast-iron guarantee before proceeding.
Usage
Meaning in Context
Business
Referring to contractual guarantees or unassailable market positions. 'The deal came with a cast-iron warranty.'
Academic
Used in history, engineering, and materials science to describe the alloy and its historical significance.
Everyday
Common in cooking ('cast-iron pan') and figurative speech ('a cast-iron excuse').
Technical
Precise terminology in metallurgy, engineering, and manufacturing for the specific ferrous alloy.
Watch out
Common Mistakes When Using “cast iron”
- Misspelling as 'cast-iron' (noun) vs. 'cast iron' (material noun). The hyphen is typical for the adjective.
- Using it as a predicate adjective without a noun: 'His excuse was cast iron' (less common) vs. 'He had a cast-iron excuse' (more common).
- Confusing with 'wrought iron', which is a different, more malleable material.
FAQ
Frequently Asked Questions
As a noun phrase for the material, it's usually 'cast iron' (two words). When used as an attributive adjective, it's often hyphenated: 'cast-iron skillet'.
Yes, figuratively. Phrases like 'cast-iron will', 'cast-iron constitution', or 'cast-iron stomach' describe a person's extreme resilience, determination, or physical toughness.
Cast iron is brittle and shaped by casting (pouring into moulds). Wrought iron is fibrous, malleable, and shaped by forging (hammering). Wrought iron is older and used for decorative work, while cast iron is stronger under compression.
It is a strong colloquial or marketing term implying an absolute, unbreakable guarantee. Legally, its strength depends on the specific contractual wording, but it conveys an intention of zero exceptions.
A hard, brittle alloy of iron, carbon, and silicon, shaped by pouring molten metal into a mould.
Cast iron is usually neutral; used in both informal and formal contexts, particularly in technical, industrial, and figurative language. in register.
Cast iron: in British English it is pronounced /ˌkɑːst ˈaɪən/, and in American English it is pronounced /ˌkæst ˈaɪərn/. Tap the audio buttons above to hear it.
Phrases
Idioms & Phrases
- “have a cast-iron stomach”
- “a cast-iron guarantee/alibi”
Learning
Memory Aids
Mnemonic
Think of a heavy, old-fashioned **IRON** frying pan that was **CAST** (poured) into a mould. Something 'cast iron' is as solid and unmoving as that pan.
Conceptual Metaphor
STRENGTH IS HARD METAL / CERTAINTY IS A SOLID OBJECT.
Practice
Quiz
In which context is 'cast iron' used figuratively?