Translation guide
The rapid increase or spread of something, often with a negative connotation. In Japanese, this concept is expressed through various nouns and verbs depending on what is proliferating—weapons, cells, information, etc.
To describe a rapid and often uncontrolled increase in the number or spread of something, such as weapons, technology, or information.
The most common and versatile term for proliferation, meaning 'diffusion' or 'spread'. Used for weapons, information, rumors, etc.
核兵器の拡散を防ぐ。
Prevent the proliferation of nuclear weapons.
誤情報の拡散が問題になっている。
The proliferation of misinformation is a problem.
Means 'rapid increase' or 'surge'. Used when the focus is on a sharp rise in numbers rather than physical spread.
スマートフォンの利用が急増している。
The proliferation of smartphone use is surging.
Often used for the spread of something undesirable, like disease, crime, or harmful ideas. Has a negative nuance.
偽ニュースの蔓延を食い止める。
Stop the proliferation of fake news.
Primarily means 'proliferation' in a biological sense, like cell multiplication. Can be used metaphorically for things multiplying rapidly.
がん細胞の増殖を抑える。
Suppress the proliferation of cancer cells.
Specifically referring to the spread of weapons, especially weapons of mass destruction.
The standard term for 'nuclear proliferation'.
核拡散防止条約
Nuclear Non-Proliferation Treaty
General phrase for 'proliferation of weapons'.
小型兵器の拡散が地域の不安定を招く。
The proliferation of small arms leads to regional instability.
Describing the biological process of rapid reproduction or multiplication.
The primary term for biological proliferation, such as cell division or population growth of organisms.
バクテリアが増殖する。
Bacteria proliferate.
Means 'breeding' or 'propagation', often used for animals and plants. Implies reproduction rather than just increase.
拡散 is neutral and simply means 'spread' or 'diffusion'. 蔓延 carries a strong negative connotation, like 'infestation' or 'rampancy', and is used for undesirable things like disease or crime.
The English word 'proliferation' is often translated as 拡散, but in some contexts a different word is more natural. For example, 'proliferation of choices' might be better expressed as 選択肢の増加 (increase in options) rather than 選択肢の拡散.
外来種が繁殖して在来種を脅かしている。
Invasive species are proliferating and threatening native species.