a dream, vision, or reverie; an idle or fanciful imagination often disconnected from reality.
彼は成功した自分を夢想して、現実の準備を後回しにしてしまった。
He daydreamed about himself succeeding and put off preparing for reality.
その小説は作者の夢想がそのまま書かれているような不思議な世界だ。
That novel is a strange world that seems to record the author's fantasies as they are.
会議中、彼は夢想にふけって発言しなかった。
During the meeting, he was lost in reverie and didn't speak.