Disappointed means feeling sad or let down because something did not happen the way you hoped or expected. It often involves a mix of frustration and loss.
From 'disappoint', originally meaning 'to undo an appointment or arrangement', from Old French 'desappointer'. The emotional sense grew from the idea of plans being broken or hopes being unset.
Buried in 'disappointed' is the idea of an 'appointment'—a meeting between your hopes and reality. When reality doesn’t show up to that meeting, you feel disappointed.
Complete word intelligence in one call. Free tier — 50 lookups/day.