名詞 letdown:

1. a feeling of dissatisfaction that results when your expectations are not realized
   同義詞：disappointment

1. The movie was a letdown.
   那電影真令人失。
2. It was a big letdown when I was not accepted by Harvard university.
   當(dāng)我的入學(xué)申請被哈佛大學(xué)拒絕時，我失望極了。

let.down

n.（名詞）
A decrease, decline, or relaxation, as of effort or energy.
放松，弛緩，衰落：努力或力量方面的減少、降低或放松
A disappointment:
失望、沮喪：
例句：
The cancellation of the game was a real letdown.
比賽取消真是令人失望

The descent made by an aircraft in order to land.
飛機的程序下降：飛機為了著陸而作的下降飛行