| No. | Item | Definition |
|---|---|---|
| 1. | actigraphy | sleep estimation from movement |
| 2. | alarm | device or sound for waking |
| 3. | alert | fully awake and attentive |
| 4. | apnea | temporary stop in breathing |
| 5. | arousal | state of being awakened |
| 6. | asleep | in the state of sleep |
| 7. | awake | not sleeping |
| 8. | awakening | the act of waking |
| 9. | bed | furniture used for sleeping |
| 10. | bedroom | room used for sleeping |
| 11. | bedtime | usual time to go to bed |
| 12. | blanket | bed covering for warmth |
| 13. | blue light | light that can delay sleep |
| 14. | body clock | internal daily timing system |
| 15. | breathing | the act of taking air in |
| 16. | caffeine | stimulant that increases alertness |
| 17. | catnap | a very short sleep |
| 18. | chronotype | natural preference for sleep timing |
| 19. | circadian rhythm | the body’s daily clock |
| 20. | comfort | physical ease and relaxation |
| 21. | conk out | fall asleep suddenly |
| 22. | consistency | staying regular over time |
| 23. | crash | fall asleep from exhaustion |
| 24. | darkness | absence of light |
| 25. | dawn | first light of day |
| 26. | deep sleep | slow-wave restorative sleep |
| 27. | doze | a light sleep |
| 28. | dream | images or thoughts during sleep |
| 29. | drift off | fall asleep gradually |
| 30. | drowsy | sleepy and hard to stay awake |
| 31. | duvet | soft quilt used on a bed |
| 32. | evening | later part of the day |
| 33. | exhausted | extremely tired |
| 34. | fatigued | very tired |
| 35. | groggy | sleepy and not fully alert |
| 36. | habit | regular repeated behavior |
| 37. | heart rate | number of heartbeats per minute |
| 38. | hypersomnia | excessive sleepiness or sleeping |
| 39. | insomnia | difficulty falling or staying asleep |
| 40. | interruption | something that breaks continuity |
| 41. | jet lag | sleep disruption after travel |
| 42. | lark | person who wakes early |
| 43. | lie-in | a morning spent sleeping late |
| 44. | light sleep | easier-to-wake sleep stage |
| 45. | lights-out | time when sleep begins |
| 46. | mattress | soft bed base for sleeping |
| 47. | melatonin | hormone linked to sleep timing |
| 48. | microawakening | a brief awakening during sleep |
| 49. | midday | middle of the day |
| 50. | midnight | twelve o’clock at night |
| 51. | morning | early part of the day |
| 52. | motionless | not moving |
| 53. | movement | physical motion |
| 54. | nap | a short sleep |
| 55. | night owl | person active late at night |
| 56. | nightmare | a frightening dream |
| 57. | nodding off | beginning to fall asleep |
| 58. | noise | unwanted sound |
| 59. | non-REM | sleep excluding REM stage |
| 60. | oversleep | sleep longer than intended |
| 61. | parasomnia | unusual behavior during sleep |
| 62. | pillow | head support in bed |
| 63. | power nap | a brief energizing nap |
| 64. | pulse | heartbeat felt in an artery |
| 65. | quilt | stitched bed covering |
| 66. | refreshed | rested and full of energy |
| 67. | relaxation | a state of calm |
| 68. | REM | dream-rich sleep stage |
| 69. | respiration | breathing |
| 70. | rest | sleep or relax to recover |
| 71. | restlessness | inability to stay still or sleep |
| 72. | ritual | set actions done regularly |
| 73. | routine | usual repeated way of doing things |
| 74. | shut-eye | sleep |
| 75. | siesta | a midday rest or nap |
| 76. | sleep | a natural state of rest |
| 77. | sleepwalk | walk while asleep |
| 78. | sleepy | ready or needing to sleep |
| 79. | slow-wave sleep | deep restorative sleep |
| 80. | slumber | sleep, especially peaceful sleep |
| 81. | snooze | a short light sleep |
| 82. | snore | breathe noisily during sleep |
| 83. | somnolence | strong sleepiness |
| 84. | temperature | degree of heat or cold |
| 85. | time in bed | total time spent in bed |
| 86. | tired | needing rest or sleep |
| 87. | tracker | device that records activity |
| 88. | turn in | go to bed |
| 89. | turning | shifting position in bed |
| 90. | undersleep | sleep less than needed |
| 91. | unwind | relax before sleep |
| 92. | wake | to stop sleeping |
| 93. | wakefulness | the state of being awake |
| 94. | warm | slightly hot |
| 95. | wearable | electronic device worn on body |
| 96. | weekday | a day from Monday to Friday |
| 97. | weekend | Saturday and Sunday |
| 98. | wind down | gradually relax before bed |
| 99. | yawn | open mouth from tiredness |
| 100. | yawning | repeated tired opening of mouth |