Cast Iron Stomach (Origin)

by Craig Shrives

What Is the Origin of the Saying "Cast Iron Stomach"?

The term "cast-iron stomach" is used for someone who can eat almost anything without feeling sick or experiencing any ill effects.

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Cast Iron Stomach (Origin)

Examples of Use:

  • Jack has a cast-iron stomach. He can eat a jar of jalapenos with no ill effects.
  • The doctor said I must have a cast-iron stomach if I've been taking that many aspirin.
  • Don't you feel sick after that pizza? You've got a cast-iron stomach, man.
The idiom "cast-iron stomach" was used in the late 19th century, but it did not become common language until the early 20th century (evidence).

More about Cast Iron

Cast iron is an alloy of iron that contains 2 to 4 percent carbon. It is often used to make pots and pans. Cast iron was produced in China as early as the 6th century BC, but it only started to emerge in Europe in 15th century (two millennia later).
When used in the saying "cast-iron stomach," there should be a hyphen because "cast-iron" is a compound adjective (i.e., an adjective made up of more than one word). The hyphen joins the words to show they are a single grammatical entity. Look at these two examples:
  • My stomach is made of cast iron.
  • (In this example, there is no hyphen. "Cast iron" is not being used as an adjective.)
  • I have a cast-iron stomach.
  • (Here, a hyphen is required. "Cast iron" is being used as an adjective, a compound adjective.)
The saying is, of course, a metaphor.

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