This is the 7699th most frequent Japanese word.
危うい
Dangerous; risky; precarious.
The word "危うい" is used here to describe the fragility or risk associated with someone's health condition.
彼の健康状態は危ういと医師が言っています。
The doctor says that his health condition is precarious.
"危うい" is applied in this context to comment on the instability or potential danger of the bridge's structure.
その橋は構造的に危うい状況にある。
That bridge is in a structurally risky state.
Here, "危うい" signifies the uncertainty and risk involved in executing a plan.