Awakening from sleep; also the manner or feeling upon waking (e.g. a good or bad awakening).
寝覚めがいい日は気分がさわやかだ。
On days when I wake up feeling refreshed, I feel cheerful.
彼は寝覚めにいつも熱いコーヒーを飲む。
He always drinks hot coffee when he wakes up.
寝覚めの悪さで一日中ぼんやりしていた。
Because I woke up poorly, I was groggy the whole day.