分子(ぶんし)

ぶんし
noun
molecule; numerator; member of a group
sciencenumber
1. molecule
The smallest unit of a chemical compound that retains its chemical properties. A scientific term used in chemistry and biology.
水(みず)の分子(ぶんし)はH2Oだ。
The molecule of water is H2O.
この物質(ぶっしつ)は分子(ぶんし)が小(ちい)さい。
This substance has small molecules.
分子(ぶんし)レベルで構造(こうぞう)を解析(かいせき)する。
We analyze the structure at the molecular level.
2. numerator
The number above the line in a fraction.
分数(ぶんすう)の分子(ぶんし)は上(うえ)の数(かず)だ。
The numerator of a fraction is the number on top.
分子(ぶんし)と分母(ぶんぼ)を約分(やくぶん)する。
Reduce the numerator and denominator.
3/5の分子(ぶんし)は3で、分母(ぶんぼ)は5だ。
In 3/5, the numerator is 3 and the denominator is 5.
3. member, element (of a group)
A person who belongs to a particular group, often used with a negative connotation to describe troublesome or dangerous members.
不穏(ふおん)分子(ぶんし)を排除(はいじょ)する。
Eliminate disruptive elements.
過激(かげき)分子(ぶんし)がデモに紛(まぎ)れ込(こ)んだ。
Radical elements infiltrated the demonstration.
反体制(はんたいせい)分子(ぶんし)として警察(けいさつ)に監視(かんし)されていた。
He was under police surveillance as an anti-establishment element.

Three distinct meanings that share the same reading:

Sense 1 (molecule) is the most common in scientific contexts.
Sense 2 (numerator) pairs with 分母(ぶんぼ) (denominator).
Sense 3 (member/element) typically appears with negative modifiers.

Common collocations

Related Words

Related: 分母(ぶんぼ) (denominator)
Related: 原子(げんし) (atom)
Related: 元素(げんそ) (element (chemical))
Compare: 粒子(りゅうし) (particle)
Compare: 化合物(かごうぶつ) (chemical compound)
general
Added 2026.2.18 8:15 · Revised 2026.9.2 13:01
11500/11769_bunshi