morning sleep

morning sleep (usually uncountable, plural morning sleeps)

1. The second sleep of the night in a biphasic sleep pattern, after the watch.
   • 2001 April, A. Roger Ekirch, “Sleep We Have Lost: Pre-Industrial Slumber in the British Isles”, in The American Historical Review‎, volume 106, number 2, American Historical Association, pages 364–365:

     Until the close of the early modern era, Western Europeans on most evenings experienced two major intervals of sleep bridged by up to an hour or more of quiet wakefulness. […] The succeeding interval of slumber was called “second” or “morning” sleep.

• second sleep
• next sleep

• dead sleep