What is another word for disgruntled?

Here are some synonyms for disgruntled, depending on the specific nuance you want to convey:

General dissatisfaction:

* Dissatisfied

* Unhappy

* Uncontented

* Displeased

* Frustrated

* Resentful

* Grieving

* Agitated

* Annoyed

* Peeved

More negative connotations:

* Bitter

* Grumbling

* Cranky

* Sullen

* Morose

* Incensed

* Furious

* Angry

* Hostile

More specific situations:

* Work: Demoralized, alienated, disillusioned

* Relationships: Hurt, betrayed, offended

The best synonym will depend on the context of your sentence and the specific emotions you want to express.