Synonyms/Hypernyms (Ordered by Estimated Frequency) of noun disappointment

2 senses of disappointment

Sense 1
disappointment, letdown -- (a feeling of dissatisfaction that results when your expectations are not realized; "his hopes were so high he was doomed to disappointment")
       => dissatisfaction -- (the feeling of being displeased and discontent; "he was never slow to express his dissatisfaction with the service he received")

Sense 2
disappointment, dashing hopes -- (an act (or failure to act) that disappoints someone)
       => failure -- (an unexpected omission; "he resented my failure to return his call"; "the mechanic's failure to check the brakes")