な亡naくなるkunaru
1.
To pass away, representing the end of life in a manner that is more gentle and respectful than the direct expression for death.
2.
To cease to live, commonly used in contexts that convey compassion or formality concerning someone's death.
3.
To leave this world, often used to honor the memory of the deceased while softening the impact of the news.
Example:
ディックは１０歳のときなくなりました。