expression, ichidan verb
be wide-awake; be unable to sleep
Describes a state where one's eyes are clear and alert, often due to excitement, worry, or caffeine, making sleep difficult.
コーヒーを飲んだせいで、夜になっても目が冴えて眠れなかった。
Because I drank coffee, my eyes were wide awake even at night and I couldn't sleep.
明日の発表
Worried about tomorrow's presentation, I ended up wide awake.