Oversleeping; sleeping past the intended time and often being late as a result.
今朝は寝坊して約束に遅れてしまった。
I overslept this morning and was late for my appointment.
寝坊しないように三つ目の目覚ましをセットした。
I set a third alarm so I won't oversleep.
彼は週末に寝坊して朝の練習を休んだ。
He overslept on the weekend and missed morning practice.
A late riser; a sleepyhead — someone who habitually sleeps late.
彼は大の寝坊で、平日でもなかなか起きない。
He is a big late riser and hardly gets up even on weekdays.
寝坊の妹に朝ごはんを起こしに行った。
I went to wake my sister, who always sleeps late, for breakfast.