vindictive
/ˌvɪndɪkˈtɪv/Definitions
1. adjective
having or feeling a strong desire for revenge; having a tendency to seek revenge
“After being fired, she became vindictive and made sure to sabotage her former employer’s projects.”
2. noun
the quality of being motivated by a desire for revenge
“Her vindictive attitude towards her ex-boyfriend was evident in the way she handled the breakup.”