microsleep
Seconds-long involuntary doze
A microsleep is a brief, involuntary episode of sleep lasting a few seconds, often occurring when someone is fatigued but trying to stay awake.
The person may appear alert—eyes open, sitting upright—yet the brain momentarily disengages.
Microsleeps are particularly dangerous while driving or operating machinery: He didn't realize he'd been microsleeping until he drifted into the next lane.
State of utter depletion
- tirednessState of needing rest
- drowsinessState of near-sleep
- somnolenceAbnormal urge to doze
- sleepinessState of needing rest
weariness · lethargy · heavy-eyed · burnout · overwork · insomnia · circadian · sluggishness
Brief failure or expiration
seconds · fleeting · split-second · instantaneous · transient · flash · sudden · brief
exhaustion
State of utter depletion
- tirednessState of needing rest
- drowsinessState of near-sleep
- somnolenceAbnormal urge to doze
sleepiness · weariness · lethargy · heavy-eyed · burnout · overwork · insomnia · circadian · sluggishness · yawning
lapse
Brief failure or expiration
momentary · seconds · fleeting · split-second · instantaneous · transient · flash · sudden · brief · imperceptible
driving
Controlling a vehicle
highway · wheel · inattention · impairment · collision · swerving · pilot · operator · machinery · workplace
nap
Brief daytime rest
siesta · shuteye · repose · break · respite · rejuvenation · recharge · restorative
- sleepnap, doze, slumber, naps, snooze
- drowsinesssleepiness, tiredness, grogginess, lethargy, fatigue
- fatigue symptomsexhaustion, tiredness, drowsiness, sleepiness, yawning
- napsnap, catnap, power nap, siesta, snooze
- consciousness statesunconscious, conscious, awake, alert, wakefulness
- dreamsnightmare, dreaming, daydream, nightmares, dreams
microsleephypervigilance
Heightened threat sensitivity
wakefulness · vigilance · sharp focus · wide awake · attentiveness