Having delicate health; not robust; weak: (Dictionary.com)
Easily broken or destroyed; fragile. (Dictionary.com)
Morally weak; easily tempted. (Dictionary.com)
Weak or unhealthy, or easily damaged, broken, or harmed: (Cambridge Dictionary)
Easily led into evil. (Merriam – Webster)
Easily broken or destroyed: Fragile. (Merriam – Webster)
Physically weak. (Merriam – Webster)
(of a person) weak and delicate. (Oxford Dictionaries)
Easily damaged or broken; weak. (Oxford Dictionaries)
Frail patients are at increased risk for mortality and prolonged institutional care after cardiac surgery.
Frail – A Medical Assessment of health.