caffein

Thân thiện

A scientist carefully measures caffeine powder in a laboratory.

Definition

Noun A bitter, crystalline alkaloid compound (C₈H₁₀N₄O₂) that acts as a central nervous system stimulant. It is naturally found in the seeds, leaves, and fruits of some plants, most notably in coffee beans and tea leaves, and is responsible for their characteristic stimulating effects on the human body.

Usage

The word "caffeine" is used to refer to the specific chemical substance itself. It is a non-count noun when referring to the compound in general, but can be used in a countable sense when referring to types or amounts. - General substance: This drink contains caffeine. - Specific amount/type: There are different caffeine found in nature, but the one in coffee is the most well-known.

Examples

• Noun:
  • The caffeine in my morning coffee helps me wake up.
  • She is trying to reduce her caffeine intake.
  • Decaffeinated coffee has had most of the caffeine removed.

Advanced Usage

• "a caffeine buzz": a feeling of alertness and energy caused by consuming caffeine.
  • I got a quick caffeine buzz from the espresso.
• "caffeine dependence": a condition where a person relies on caffeine to function normally or experiences withdrawal symptoms without it.
  • His headaches are a sign of mild caffeine dependence.

Variants and Related Words

• Caffeinated (adj): Describing a beverage or product that contains added caffeine.
  • I prefer caffeinated soda over the caffeine-free kind.
• Decaffeinated (adj): Describing a product from which most of the caffeine has been removed.
  • Would you like regular or decaffeinated coffee?
• Caffeine-free (adj): Containing no caffeine.
  • This herbal tea is naturally caffeine-free.

Synonyms

• Theine: An archaic term for the caffeine found in tea.
• Methyltheobromine: A less common chemical name for caffeine.

Related Phrases

• "caffeine kick": similar to "caffeine buzz," referring to the sudden energizing effect.
  • I need the caffeine kick from this soda to finish my work.
• "caffeine crash": a feeling of fatigue that can follow after the stimulating effects of caffeine wear off.
  • After the caffeine crash, I felt even more tired than before.

Học thuật

Noun

1. a bitter alkaloid found in coffee and tea that is responsible for their stimulating effects

Từ đồng nghĩa

• caffeine