cruel
US /ˈkruː.əl/
UK /ˈkruː.əl/

1.
willfully causing pain or suffering to others, or feeling no concern about it
:
•
It was cruel of him to tease the small child.
•
The king was known for his cruel punishments.
2.
causing pain or suffering
:
•
The disease has a cruel effect on the body.
•
Life can be very cruel sometimes.