醒来 is a resultative verb compound meaning 'to wake up'. The verb 醒 (wake) is followed by the directional complement 来 (come), indicating the coming-into-a-state of being awake. You can insert 得 (possible) or 不 (impossible) between the two characters: 醒得来 (able to wake up), 醒不来 (can't wake up). It typically appears without a direct object; if you want to mention the source, use 从……中 (from...). Don't confuse it with 起床 (get out of bed) or the stative 醒了 (have woken up).