1. superlative form of flint; most resembling or containing flint; hard and unyielding
Usage: superlative degree; often used figuratively to describe a person's character or expression
2. superlative form of flinty; having a hard, cold, or unfeeling quality; showing no sympathy
Usage: figurative use; describes personality or demeanor

Examples

• The flintiest rocks in the riverbed were perfect for starting a fire.
• She had the flintiest expression on her face when she heard the bad news.
• His flintiest resolve never wavered, even under intense pressure.
• The flintiest soil in the region made farming extremely difficult.
• With a flintiest gaze, the judge delivered the verdict.
• The old prospector's flintiest determination drove him to search for gold for decades.