Unmerciful (adjective)

Not showing mercy or compassion; harsh and merciless.

Origin:

From un- (meaning 'not') + merciful (meaning 'compassionate, showing mercy').

Examples:

1. The judge was unmerciful in his sentencing.
2. The unforgiving desert was an unmerciful place to be stranded.
3. The tyrant was known for his unmerciful rule over the kingdom.
4. The storm was unmerciful, causing widespread damage.
5. The unmerciful bully tormented the younger students relentlessly.