To disappoint someone means to fail to meet their hopes or expectations. When your friend promises to come to your birthday party but cancels at the last minute, you feel disappointed. When you study hard for a test but get a lower grade than you expected, the result disappoints you.

Disappointment happens in that gap between what we hoped would happen and what actually happens. Maybe you practiced for weeks hoping to make the basketball team, or you expected a package to arrive on Saturday, or you thought the new book by your favorite author would be as good as the last one. When reality falls short of these hopes, that's disappointment.

The word can describe both the action (disappointing someone) and the feeling (being disappointed). A disappointment is something or someone that fails to live up to expectations. If the sequel to a great movie turns out boring, people call it a disappointment.

Everyone experiences disappointment, and everyone disappoints others sometimes, even when trying their best. The sting of disappointment often fades, especially when you adjust your expectations or find a new path forward.