Something or someone that disappoints: that which causes disappointment.
An example or the act of disappointing: a circumstance in which a positive expectation is not achieved.
The feeling or state of being disappointed: a feeling of sadness or frustration when something is not as good as one hoped or expected, or when something bad unexpectedly happens.
The state of being disgruntled, usually displayed in a stereotypical form such as frowning and annoyance; the acts of sulky dissatisfaction.