robustness

n. strength, power; stoutness, soundness

Robustness is the quality of being able to withstand stresses, pressures, or changes in procedure or circumstance. A system, organism or design may be said to be "robust" if it is capable of coping well with variations (sometimes unpredictable variations) in its operating environment with minimal damage, alteration or loss of functionality.
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Noun
1. the property of strong in constitution
(synonym) hardiness, lustiness
(hypernym) strength

(n.)
The quality or state of being robust.
  

The condition of a product or process design that remains relatively stable, with a minimum of variation, even though factors that influence operations or usage, such as environment and wear, are constantly changing.