1.
density (physical); concentration
The amount of a substance per unit of volume or area. A standard scientific term. Composed of 密 (dense) + 度 (degree).
水の密度は約1g/cm³だ。
The density of water is approximately 1 g/cm³.
人口密度が高い地域だ。
It is an area with high population density.
鉄は木より密度が大きい。
Iron has a greater density than wood.
2.
density; intensity; richness (figurative)
The degree of substance or content packed into something, such as time, a schedule, or a piece of work. Implies fullness or richness of content.
密度の濃い一日だった。
It was a packed and productive day.
練習の密度を上げる必要がある。
We need to increase the intensity of practice.
密度の高い授業で疲れた。
I was tired after an intense, content-packed class.
USAGE:
The scientific sense (sense 1) is used in physics, chemistry, and geography. The figurative sense (sense 2) is common in everyday speech, describing how packed or rich with content something is.
COMMON COLLOCATIONS:
- 人口密度 (population density)
- 密度が高い (high density / packed with content)
- 密度の濃い (dense, rich — figurative)
- 密度を上げる (to increase intensity/density)