Robustness
Etymology
From Latin "robustus" ("strong, oaken"), from "robur" ("oak, strength"), plus "-ness." The engineering and systems sense — tolerance of variation and failure — became prominent in the 20th century.
noun · /roh-BUST-ness/
The ability of a system to keep working well despite stress, error, or unexpected conditions.
What it names
A handle for the quality you want in bridges, code, and plans — they hold up when reality doesn’t cooperate.
Example
The system’s robustness showed when a server failed and users noticed nothing.
Related idea
Resilience is about recovering after a blow; robustness is about not buckling in the first place. A cousin, antifragility, goes further — actually improving under stress.