1. impossible to break or destroy; unbreakable
Usage: formal
2. that cannot be violated or infringed upon
Usage: formal; legal

Examples

• The ancient fortress seemed infrangible against enemy attacks.
• She believed her principles were infrangible, no matter the pressure.
• The contract contained infrangible clauses that could not be altered.
• His infrangible will helped him overcome every obstacle.
• The constitution guarantees certain infrangible rights to all citizens.
• The diamond’s infrangible structure made it perfect for industrial use.