infirm

1. ADJ A person who is infirm is weak or ill, and usually old. (常指因年邁而) 躰弱的[正式]

...her aging, infirm husband. …她那年邁躰弱的丈夫。

2. N-PLURAL The infirm are people who are infirm. 躰弱者

We are here to protect and assist the weak and infirm. 我們來這裡保護和幫助病弱者。