커피나 차 등에서 발견되는 백색의 결정성 화합물로, 중추 신경을 자극하여 각성 효과를 일으키는 물질.
A bitter white alkaloid found especially in coffee, tea, and cocoa beans which acts as a stimulant for the central nervous system.
예문:
"Excessive caffeine intake can cause jitteriness and difficulty falling asleep at night."
"The athlete was tested for caffeine levels to ensure they didn't exceed the legal limit for the competition."
"Many people rely on a morning cup of coffee for a quick boost of caffeine to start their day."