on death's door
- dyingCeasing to live
- terminalAt the endpoint
- fadingGradual loss of intensity
- knockingStriking to announce presence
- thresholdPoint of beginning
brink · last breath · critical · hanging on · slipping away · deathbed · pale · wasting · hospice · feeble · gasping · weakening · ebbing · twilight · end stage · mortal · expiring · last rites
health/vitality
on death's doorfit as a fiddle
In excellent physical condition
in the pink · hale and hearty · healthy as a horse · in tip-top shape · fighting fit
life force/energy
on death's doorfull of life
Energetic and animated
alive and kicking · vivacious · vigorous · sprightly · energetic