An anticlimax; the feeling of disappointment or deflation when something doesn't live up to expectations or when excitement suddenly fades.
コンサートのアンコールがなくて、観客は拍子抜けした。
There was no encore at the concert, and the audience felt anticlimactic.
彼の大きな発表は期待外れで、場が拍子抜けした。
His big announcement was disappointing and the mood fell flat.
サプライズがばれてしまい、みんな拍子抜けした。
The surprise was found out and everyone was let down.
テストがあまりにも簡単で、学生は拍子抜けしていた。
The test was so easy that the students were left feeling anticlimactic.