adjective

Savagely cruel; exceedingly brutal.

many early child-rearing practices were barbarous by modern standards

cruel,brutal,barbaric,brutish,bestial,savage,vicious,fierce,ferocious,wicked,nasty,ruthless,remorseless,merciless,villainous,murderous,heinous,nefarious,monstrous,base,low,low-down,vile,inhuman,infernal,dark,black,black-hearted,fiendish,hellish,diabolical,ghastly,horrible