noun
pent-up resentment; grudges and hard feelings
Refers to accumulated bitterness and ill will, often from past grievances. Commonly used in phrases like 恨みつらみを言う (to air one's grievances) or 恨みつらみがある (to harbor resentment).
彼は酒を飲むと、昔の恨みつらみを言い始める。
When he drinks, he starts airing old grudges.
二人の間には長年
Years of pent-up resentment have built up between the two.