To add support for this: In Japan there's a word that literally means "second sleep". 二度寝 (ni.do.ne) It's a word still in common use today. It simply refers

To add support for this: In Japan there's a word that literally means "second sleep". 二度寝 (ni.do.ne) It's a word still in common use today. It simply refers to when you wake up in the morning but still feel tired or groggy so you sleep again.