unforgiving
UK: ʌnfəˈɡɪvɪŋ | US: ʌnfərˈɡɪvɪŋ
adj. not willing to forgive or show mercy; harsh or relentless
adj. (of conditions or circumstances) extremely severe or unyielding
The word "unforgiving" combines the prefix "un-" (Old English "un-," meaning "not") with the verb "forgive" (Old English "forgiefan," from "for-" [completely] + "giefan" [give], implying "to give up resentment"). The suffix "-ing" turns it into an adjective. Historically, "forgive" evolved from the idea of "giving up" a debt or grievance. Adding "un-" flips the meaning to describe someone or something that refuses to pardon or relent.
The desert climate is unforgiving to those unprepared for its extremes.
She gave him an unforgiving stare after his betrayal.
The teacher’s unforgiving grading policy left no room for mistakes.
His unforgiving nature made reconciliation impossible.
The mountain’s unforgiving terrain challenged even experienced hikers.