カフェイン かふぇいん noun caffeine food 1. caffeine The stimulant found in coffee, tea, and many soft drinks that helps keep one awake and alert. コーヒーにはカフェインが多(おお)い。🔊 Coffee has a lot of caffeine. 夜(よる)はカフェインを取(と)らないようにしている。🔊 I try not to take in caffeine at night. カフェインの取(と)りすぎは眠(ねむ)れなくなる原因(げんいん)になる。🔊 Taking in too much caffeine can be a cause of being unable to sleep. A loanword (from English "caffeine"). Found in coffee, tea, and energy drinks; valued as a stimulant but a concern when consumed in excess.Common collocationsカフェインを取(と)る: take in / consume caffeineカフェイン入(い)り: containing caffeineカフェインレス: caffeine-free (decaf)カフェインの取(と)りすぎ: too much caffeine general Added 2026.5.23 11:04 · Revised 2026.9.2 13:02 27500/27911_kafein