on its last legs
- worn outDepleted through overuse
- exhaustedUtterly depleted of energy
- dyingCeasing to live
- failingFlaw in one's nature
- crumblingBreaking down gradually
decrepit · fading · breaking down · deteriorating · threadbare · rickety · tottering · wheezing · sputtering · gasping · limping · hanging by a thread · on borrowed time · past its prime · run down · clapped out · kaput · junker
vitality/condition
on its last legsgoing strong
Continuing vigorously, undiminished
thriving · flourishing · in tip-top shape · robust · in full swing