merciless
Definitions
Showing no mercy or pity; cruel.
Relentless or unsparing in intensity or severity.
Examples
The merciless sun beat down on the desert travelers all afternoon.
The critic wrote a merciless review that destroyed the young author's confidence.
He showed a merciless attitude toward his opponents during the final match.
Synonyms
ruthless pitiless cruel remorseless heartless unforgiving harsh