noun
Primary meaning: a secondary product obtained during the manufacture of something else. Used in industrial, economic, and scientific contexts.
石油精製の副産物として硫黄が得られる。
Sulfur is obtained as a by-product of petroleum refining.
noun
Extended figurative use: an unintended but often beneficial result, a secondary effect, or a consequence of some action or development.
この研究の副産物として、新しい治療法が見つかった。
As a spin-off of this research, a new treatment method was discovered.
都市開発の副産物として交通渋滞が悪化した。
Traffic congestion worsened as a side effect of urban development.