from The Century Dictionary.
- To sleep less than is necessary.
from Wiktionary, Creative Commons Attribution/Share-Alike License.
- verb intransitive To
from Wiktionary, Creative Commons Attribution/Share-Alike License
There are plenty of people who overwork without economic necessity, undersleep, undereat, don't let themselves relax, damage their joints with punitive exercise, etc.
Better to undersleep than oversleep, they figured.
Without protest, and without notice until too late, teachers often neglect their own health at home and at school, -- recklessly overwork, undersleep, and undernourish; ruin their eyes, their digestion, and their nerves.
Youth needs overexertion to compensate for underexertion, to undersleep in order to offset oversleep at times.