na-adjective, noun which may take the genitive case particle 'no', noun
absorbed in; crazy about; devoted to
The most common modern use. Often appears as 〜に夢中だ or 〜に夢中になる for being very interested in something, or 夢中で for doing something with full attention.
He is crazy about the new game.
The children are absorbed in catching insects.
forgetting oneself; trance; daze; delirium
Describes a state of losing ordinary self-awareness through panic, excitement, pain, ecstasy, or confusion. In everyday Japanese, this often appears in phrases like 夢中で or 無我夢中で, meaning one acts without thinking clearly.
When I heard there was a fire, I rushed outside without thinking.
She called for help frantically.
within a dream; while dreaming
Literal use meaning “inside a dream” or “while dreaming.” In modern everyday Japanese, 夢の中 is much more usual; this sense of 夢中 is literary or old-fashioned.
In old writing, 夢中 can mean “in a dream,” as in “to see one's hometown in a dream.”
He's crazy about soccer.
She's totally infatuated with that actor right now.
When I noticed the fire, I dashed outside without even thinking.
夢中 (as in 夢中になる) describes being absorbed or engrossed in something, whereas 心を奪われる emphasizes a sudden, strong emotional pull toward someone or something.
夢中 conveys being so absorbed that one forgets everything else, while 一心に focuses on the deliberate singleness of purpose behind an action.