1.
sleepyhead; someone who oversleeps
A casual, affectionate or teasing term for someone who oversleeps or has trouble getting up, built from 寝坊 (oversleeping) plus the familiar suffix 〜すけ.
この寝ぼすけ!
You sleepyhead!
寝ぼすけ is a casual, often affectionate word for a habitual late riser, built from 寝坊 (oversleeping) plus the familiar, slightly mocking suffix 〜すけ found in other nicknames.
Usage
Mostly used teasingly among family or friends, or when talking about children; too casual for formal writing.