n. A brief period (usually only a few seconds) in which the brain enters a sleep state regardless of the activity the person is performing at the time.

Example Citation:
"If we ignore sleep needs and get behind the wheel of a car, a catastrophe can happen. It only takes a few seconds—just long enough for a tired body to steal needed 'microsleep'—to run off the road or into an oncoming car."
—Jaine Carter and James D. Carter, "Everyone Must Cope with Sleep Problems," Scripps Howard News Service, April 18, 1999

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