dissatisfaction; discontent; displeasure
A formal noun or adjectival noun expressing a state of being unsatisfied or discontented, often used in serious or official contexts.
He was dissatisfied with the result.
If there is anything you are dissatisfied with, please don't hesitate to say so.
Compound of 不 (fu, 'not') + 満足 (manzoku, 'satisfaction'). The kanji 不 negates the following word, forming a straightforward antonym of 満足.