1.
absentminded; one's mind is elsewhere; distracted
Describes a state where someone is physically present but mentally preoccupied with something else. Literally, 'the heart/mind is not here.'
A classical Japanese expression meaning 'the heart is not here.' Uses the classical negative form あらず (modern: ない) of ある. Despite its literary origin, it is widely used in modern Japanese to describe someone who is distracted or preoccupied.
Etymology
From the classical Chinese text 大学 (Great Learning): 心ここに在らざれば視れども見えず — 'When the mind is not present, one looks but does not see.' The phrase became a common Japanese idiom.
Usage
Typically used as a predicate (心ここにあらずだ) or as a modifier (心ここにあらずの状態). Describes someone whose thoughts are obviously elsewhere — during a meeting, a conversation, or a task.