Getting out of bed; rising from sleep. Commonly used as a noun or as the verb 'to get up' (起床する) referring to waking and leaving bed.
毎朝六時に起床して散歩に行く。
I get up at six every morning and go for a walk.
受験生は規則正しい起床が大切だ。
Regular wake-up times are important for exam students.
看護師が患者の起床を手伝った。
A nurse helped the patient get out of bed.