noun
first thing after waking up; as soon as getting up
Refers to the period immediately after waking up, often used in phrases like 起き抜けに or 起き抜けの. Commonly used to describe actions or states right after rising.
起き抜けにコーヒーを飲むのが習慣です。
It's my habit to drink coffee first thing after waking up.
起き抜けの頭では難しいことは考えられない。
I can't think about difficult things with a just-woken-up head.
寝起き can refer to both waking up and going to bed, or the state of just having woken up, but 起き抜け specifically emphasizes the immediate post-waking period.
Compound of 起き (oki, 'waking up', continuative form of 起きる) and 抜け (nuke, 'coming out', continuative form of 抜ける), literally 'just out of waking up'.