粒子(りゅうし)

りゅうし
noun
particle; grain; corpuscle
academictechnical
1. particle; grain; fine piece
A very small piece of matter. Used in scientific contexts for subatomic particles and in everyday contexts for fine grains of sand, powder, etc.
微細(びさい)な粒子(りゅうし)が空気中(くうきちゅう)に漂(ただよ)っている。
Fine particles are floating in the air.
素粒子(そりゅうし)物理学(ぶつりがく)は宇宙(うちゅう)の成(な)り立(た)ちを解明(かいめい)する学問(がくもん)だ。
Particle physics is the study of how the universe is structured.
PM2.5は直径(ちょっけい)2.5マイクロメートル以下(いか)の粒子(りゅうし)のことで、肺(はい)の奥(おく)まで入(はい)り込(こ)むため健康(けんこう)に悪(わる)い。
PM2.5 refers to particles with a diameter of 2.5 micrometers or less, which are harmful to health because they penetrate deep into the lungs.

A compound of 粒(りゅう) (grain) and 子(し) (small thing). Used widely in both scientific and everyday contexts.

Compounds

Similar words

  • 粒(つぶ) is the everyday word for a grain or bead
  • 粒子(りゅうし) is more technical and scientific
  • 分子(ぶんし) means molecule, which is a specific type of particle

Related Words

Compare: 分子(ぶんし) (means molecule, which is a specific…)
general
Added 2026.3.4 17:03 · Revised 2026.9.2 13:01
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