Wiktionary
n. Any death that takes place at an unusually early age, or before the person's potential has been fully realized
Usage examples of "untimely death".
She was a prudent woman, not easily cowed and rather older than he was, a late child of mature parents and after the untimely death of her younger brothers and older sister the only remaining direct heir.
And Hugh's restored life means King Stephen's untimely death, unless you can reach him and stop him, stop your son.
They are sending, this cycle, a message to the princes people, telling them of their rulers untimely death.
Indeed, I marveled at their tolerance in having taken me in at all, and in lavishing so much care upon me, considering that I had been the primary cause of their mother's untimely death.
But the effect of his promise was disappointed by the sultan's untimely death: amidst the care of the most skilful physicians, he expired of an apoplexy at Akshehr, the Antioch of Pisidia, about nine months after his defeat.
The elf was trained in the blade's use, but, due to circumstanceperhaps his untimely deathsuch information was not passed along to future generations.