What is the synonym for embittered?

Here are some synonyms for embittered, depending on the specific nuance you're looking for:

Stronger/more negative:

* Resentful

* Vindictive

* Bitter (the most direct synonym)

* Cynical

* Hateful

* Venomous

* Rancorous

* Spiteful

More neutral:

* Disillusioned

* Disgruntled

* Sour

* Acerbic

* Acrimonious

* Wounded (implies a sense of hurt or pain)

* Haunted (implies a sense of past trauma)

The best synonym will depend on the context of your sentence.