bowelless
cruel
dog-eat-dog
flinty
griefless
hard
harsh
heartless
impenitent
inclement
inexorable
merciless
pitiless
regretless
relentless
remorseless
ruthless
shameless
sorrowless
unapologetic
unashamed
uncompassionate
uncompassioned
uncontrite
unfeeling
unforgiving
ungrieving
unmerciful
unpitiful
unpitying
unregretful
unregretting
unrepentant
unrepining
unrueful
unsorrowful
unsorrowing
unsorry
unsympathetic
unsympathizing
unyielding
without mercy
remorseful