lost in thought

Being preoccupied with one's thoughts rather than paying attention to reality.

Japanese Meaning

現実を無視して、自分の考えに没頭している状態 / 周囲に注意を払わず、深く思索に耽っている様子

Marie sat at the café table, lost in thought as rain tapped the window.

マリーはカフェのテーブルに座り、雨が窓をたたく中、物思いにふけっていた。

Sense（1）

Being preoccupied with one's thoughts rather than paying attention to reality.

more lost in thought

（ comparative ）

most lost in thought

（ superlative ）