unforgiving
Definitions
Unwilling or unable to forgive; showing no mercy.
Harsh, relentless, or difficult to endure, especially regarding conditions or terrain.
Examples
The mountain climber struggled against the unforgiving terrain and freezing winds.
She realized that the unforgiving nature of the desert made it impossible to survive without enough water.
The industry is known for being unforgiving to those who fail to innovate.
Synonyms
implacable merciless relentless ruthless vindictive harsh pitiless
Antonyms
forgiving merciful lenient compassionate tolerant clement charitable