A state of stunned bewilderment or being dumbfounded; so shocked or surprised that one is unable to react.
失敗の知らせを聞いて彼は茫然自失のまま座り込んだ。
When he heard the news of the failure, he sat down, dumbfounded.
事故現場で茫然自失している人が何人かいた。
There were several people at the accident scene who were in a daze.
試験の結果を見て、彼女は茫然自失とした表情を浮かべた。
Looking at the exam results, she had a stunned expression.