disappointment
1. [ noun ] a feeling of dissatisfaction that results when your expectations are not realized
Synonyms: letdown
Examples:

"his hopes were so high he was doomed to disappointment"

Related terms: dissatisfaction frustration disappoint
2. [ noun ] an act (or failure to act) that disappoints someone
Synonyms: dashing_hopes disappointing
Related terms: failure disappoint
Similar spelling:   disappointed
  disappointing
  disappointedly
  disappointingly