1.to make someone feel unhappy because something they hoped for does not happen or is not as good as they expected [lo]
If things or people disappoint you, they are not as good as you had hoped, or do not do what you hoped they would do. [co]
1) He is deeply disappointed.
2) I was disappointed to find that you were out.
3) You’ll be disappointed if you hear her sing.
4) The news of his failure in the examination greatly disappointed his parents.
5) He was disappointed by the lack of response from spectators.
[lo] LONGMAN Advanced AMERICAN DICTIONARY
[co] Collins COBUILD English Dictionary