biphasic sleep

Definitions

1. The practice of sleeping twice per night, interrupted by a period of wakefulness; common in the days before electric lighting during the season with longer night.
   uncountable
2. The practice of taking a regular nap during the afternoon and sleeping fewer hours at night.
   uncountable

Examples

“Beginning in the 1700s, the industrial revolution—its light⟳, its caffeine, its clocks, and above all, its work⟳ schedules—took Europe’s biphasic sleep⟳ in its hairy arms and mushed the two phases together.”

CEFR level