Acrimonious (adjective)

1. Bitter, angry, or nasty in tone or character.
2. Characterized by bitterness or resentment, especially in a prolonged argument or dispute.

Origin:

Late 16th century (originally in the sense "bitter in taste"): from latin acrimoniosus, from acrimonia "bitterness, harshness", from acer "sharp, bitter".

Examples:

1. The divorce proceedings were acrimonious and full of accusations.
2. The acrimonious debate between the two politicians lasted for hours.
3. The meeting between the union and management ended in an acrimonious manner.
4. The breakup of the band was acrimonious, with members blaming each other.
5. The acrimonious discussion between the two neighbors ended with a call to the police.