Most flint-like; the hardest, coldest, or most unyielding in comparison to all others.
Superlative form of 'flinty' using the '-est' suffix (from Old English '-est'). Standard superlative formation.
The superlative '-est' and comparative '-er' are among the oldest grammatical features in English, inherited directly from Proto-Germanic and barely changed in 1,500 years.
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