Vengeful means hungry to pay somebody back for a wrong. Not angry — planning.
The patience is what makes the word frightening, since a vengeful person is prepared to wait. It describes people, gods and, in fiction, ghosts. The noun is vengeance, which is grander and more biblical than revenge and belongs to declarations rather than to squabbles. Vindictive is the close neighbour and is nastier and pettier, since a vindictive person takes revenge out of all proportion to the offence.
1adjectivevengefulDetermined to take revenge for a wrong.
“He was not a vengeful man, whatever they said about him.”
From venge + ful.
Etymology from Wiktionary, CC BY-SA