Definition

Noun: A stage of sleep characterized by the absence of rapid eye movements and, typically, the absence of dreaming. It constitutes the majority of a normal sleep cycle and includes several substages progressing from light to deep sleep.

Usage

This term is used in scientific, medical, and psychological contexts to describe a specific physiological state within the sleep cycle. It is often abbreviated as NREM sleep.

Examples

• Noun:
  • Most of the night is spent in nonrapid eye movement sleep, which is essential for physical restoration.
  • The study compared brain wave patterns during nonrapid eye movement sleep and REM sleep.
  • Disorders affecting nonrapid eye movement sleep can lead to feelings of unrefreshing rest.

Advanced Usage

• "slow-wave sleep (SWS)": This is a specific, deep stage within nonrapid eye movement sleep, also known as NREM Stage 3.
  • The most restorative phase of nonrapid eye movement sleep is slow-wave sleep.

Variants and Related Words

• NREM sleep (n): The standard abbreviation for nonrapid eye movement sleep.
  • The sleep cycle alternates between NREM and REM stages.
• Quiet sleep: An alternative term sometimes used, particularly in developmental psychology.
• Orthodox sleep: A less common synonym used in some scientific literature.

Synonyms

• Slow-wave sleep (specifically for its deepest stage)
• Quiet sleep
• Synchronized sleep (referring to the synchronized brain wave patterns)

Antonyms

• REM sleep (n): Rapid eye movement sleep, the stage associated with dreaming and brain activity similar to wakefulness.
  • Dreaming is most vivid during REM sleep, not during nonrapid eye movement sleep.
• Paradoxical sleep: Another term for REM sleep.

Noun

1. a recurring sleep state during which rapid eye movements do not occur and dreaming does not occur; accounts for about 75% of normal sleep time