Designed or treated so that it will not fracture or break easily under normal conditions.
From fracture + proof (from Old French prover, 'to test'). Proof originally meant 'tested' and came to mean 'resistant to' through the sense of having been proven against damage.
Fractureproof glass was a game-changer for car safety—it's actually laminated so cracks form a spiderweb pattern instead of shattering, protecting the driver from becoming a human pincushion.
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