unforgiving

adj

1. Unwilling or unable to forgive or show mercy.

   “The electorate was in an unforgiving mood.”

2. (figuratively)Having no allowance for weakness.

   “The unforgiving Arctic climate makes short work of the unprepared.”

   “In a raucous atmosphere, it was an unforgiving and physical contest from the start. Grant Hanley conceded the first free-kick within the opening 20 seconds, setting the tone for a busy and thankless evening for Serbian referee Milorad Mazic.”

   “The line may be very scenic, but it runs through areas exposed to some extreme and unforgiving weather that does its worst on station buildings and the infrastructure!”

   “The terrain in Ukraine’s south is unforgiving for attackers, with wide open fields and little high ground, and Ukrainian troops are meeting staunch resistance from Russian forces.”

verb

1. (form-of, gerund, participle, present)present participle and gerund of unforgive