A disappointment; something or someone that fails to meet expectations, causing let-down.
映画は宣伝ほど面白くなくて期待はずれだった。
The movie wasn't as interesting as the hype and was disappointing.
プレゼントが安物で期待はずれだった。
The gift was cheap and a let-down.
彼の結果は期待はずれで、皆ががっかりした。
His results were disappointing and everyone was let down.
期待はずれに終わることもあるので、準備しておこう。
Since things can end up disappointing, let's be prepared.