Resentment (noun)

1. A feeling of anger or bitterness towards someone or something.
2. A feeling of indignant or offended by a perceived wrong.

Origin:

From the verb "resent" which comes from the latin word "resentire" meaning "to feel again".

Examples:

1. The resentment between the two countries has been brewing for decades.
2. His resentment towards his father was palpable.
3. She felt a deep sense of resentment towards her former boss.
4. The resentment built up over time and eventually boiled over.
5. His resentment was evident in the way he spoke to her.