Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English


English definition of “cast-iron”


adjective     /ˌkɑːstˈaɪən/ US  /ˌkæstˈaɪrn/
cast-iron guarantee, alibi, etc. a guarantee , alibi , etc. that can be trusted completely : Can you give me a cast-iron guarantee that the work will be completed on time ?CertaintyConfidence and self-assurance [before noun] very strong : He has a cast-iron stomach - he can eat anything.Power and intensityEnergy, force and powerHard and firm
(Definition of cast-iron adjective from the Cambridge Advanced Learner's Dictionary & Thesaurus © Cambridge University Press)
Focus on the pronunciation of cast-iron

Browse related topics

You are looking at an entry to do with Hard and firm, but you might be interested in these topics from the Weight and firmness topic area:

More definitions for “cast-iron”

Definitions of “cast-iron” in other dictionaries

Word of the Day


a skilled and trained cook who works in a hotel or restaurant, especially the most important cook

Word of the Day


Read our blog about how the English language behaves.

Learn More

New Words

Find words and meanings that have just started to be used in English, and let us know what you think of them.

Learn More