Other forms: disappointed, disappointing, disappoints
To disappoint somebody is to let them down by not being what they hoped for. The thing arrived, and it was less than expected.
The word describes the gap between expectation and reality, which is why raising expectations is such a risk. It works on people and on things, so a film can disappoint an audience. The passive is very common, as in I was disappointed with the result, and British English uses disappointed in somebody as a specific and rather crushing reproach from a parent or teacher. The noun is disappointment.
1verbdisappointTo fail to meet someone's hopes or expectations.
“The ending disappointed almost everybody.”
Middle French
desapointer
English, today
disappoint
From Middle French desapointer (compare French désappointer). The word originally meant to "dispossess of appointed office", and eventually broadened to mean "to frustrate the expectations or desires of" and "defeat the realization or fulfillment of".
Etymology from Wiktionary, CC BY-SA