
Ironclad
Beyond Dispute
Use 'ironclad' to describe something so certain that it cannot be questioned.

His alibi was ironclad; the jury believed him instantly.
Strong Assurance
'Ironclad' can express a guarantee or promise deemed extremely reliable.

The store's ironclad return policy made customers feel confident.
Compare with
ImperviousInflexibleRigidRobustStrongSturdyToughYield
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