venge ‧ ful /ˈvendʒf ə l/ BrE AmE adjective literary
[ Date: 1500-1600 ; Origin: venge 'vengeance' (16-17 centuries) , from venge 'to avenge' (13-20 centuries) , from Old French venger ; ⇨ ↑ vengeance ]
very eager to punish someone who has done something bad OPP forgiving :
a vengeful god