The quality or state of being flint-like; hardness, coldness, or unyielding character.
From 'flinty' (adjective) plus the noun-forming suffix '-ness' (from Old English '-ness'). Creates abstract nouns indicating qualities or states.
The '-ness' suffix is English's most reliable way to create abstract nouns from adjectives—happy becomes happiness, sad becomes sadness. It works so well that we barely notice its power.
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