1.
specific gravity; relative density
In physics, the ratio of a substance's density to that of water. A value above 1 means the substance sinks in water.
金は比重が大きい。
Gold has a high specific gravity.
油は水より比重が小さい。
Oil has a lower specific gravity than water.
物質が水に浮くかどうかは比重で決まる。
Whether a substance floats in water is determined by its specific gravity.
2.
relative importance; weight; proportion
Figuratively, how large a share or how much importance something occupies within a larger whole.
彼の生活では仕事の比重が大きい。
Work takes up a large share of his life.
最近、生活の中で趣味の比重が増えた。
Lately, hobbies have come to take up a bigger part of my life.
その会社は海外事業の比重を年々高めている。
The company is raising the weight of its overseas business year by year.
Sense 1 is a physics term; sense 2 is a common figurative extension meaning how large a share or how much importance something holds.
COMMON COLLOCATIONS:
- 比重が大きい / 小さい: to have a high / low specific gravity; to take up a large / small share
- 比重を高める: to increase the weight given to something
- 比重を占める: to occupy a proportion
SIMILAR WORDS:
- 密度: density — mass per unit volume; 比重 is density compared with water
- 割合: proportion; ratio — overlaps with sense 2 but is purely numerical, without the nuance of importance