cast-iron
noun
Definitions
A hard and brittle, but strong, alloy of iron, carbon, and silicon, formed by casting in a mould.
Example: Cast iron is popular for cookware where an even heating temperature is important.
adjective
Definitions
Made of cast iron.
Example: I use a cast-iron skillet for frying pancakes.
Durable; tough; resiliant.
Example: Ernest has a cast-iron constitution and never gets sick.
Inflexible or without exception.
Example: The school's cast-iron policy on admissions fees left no leeway for needy students.