resentment
n. C / Un. a feeling of anger or unhappiness because you think something is unfair. You might feel this when someone else gets something you wanted.
n. a persistent feeling of ill will or bitterness arising from a sense of being wronged or insulted. Often associated with perceived injustice or lack of recognition.
He felt a lot of resentment toward his boss.
Years of being overlooked for promotions led to a deep sense of resentment among the senior staff members.
The treaty was signed under duress, sowing seeds of resentment that would eventually destabilize the region's fragile peace for decades to come.
From resent + -ment, after Middle French and French ressentiment (in Old French as recentement), from an archaic usage of the verb ressentir via Old French sentir, from Latin sentiō, sentīre (“to feel”). Compare Italian risentimento, Portuguese ressentimento, and Spanish resentimiento. Doublet of resentiment and ressentiment, the former attested slightly earlier.
Uncountable in its general sense; countable when referring to specific instances of the feeling. Often takes the preposition 'toward' or 'against'.