proliferation

American  

[pruh-lif-uh-rey-shuhn] / prəˌlɪf əˈreɪ ʃən /

noun

1. the growth or production of cells by multiplication of parts.

2. a rapid and often excessive spread or increase.

   nuclear proliferation.

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proliferation British  

/ prəˌlɪfəˈreɪʃən /

noun

1. rapid growth or reproduction of new parts, cells, etc

2. rapid growth or increase in numbers

3. a great number

   done up in a proliferation of fancy frills

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Etymology

Origin of proliferation

First recorded in 1855–60; proliferate + -ion

Explanation

Proliferation is a rapid multiplication of parts or the increase in the number of something. Nuclear proliferation is a rapid increase of nuclear weapons. The proliferation of any living thing will often create an overpopulation problem and cause an environmental imbalance. A proliferation of fuzzy koala bears might seem kind of nice, but these cute little creatures would soon eat up all the eucalyptus, running out of food and causing problems for other species. We almost always use this word to describe stuff we don't want to increase rapidly. The excessive proliferation of mutated cells, for instance, is how cancer grows.

Example Sentences

Also distorting numbers are what’s called zero-hours contracts as well as the growing number of the self-employed, gig workers and the proliferation of internships, none of which are captured in official statistics.

From MarketWatch • Apr. 15, 2026

The rapid proliferation of drones has made many of those weapons less relevant, and spurred Ukrainian rag-tag arms producers to become global leaders in drone warfare and anti-drone systems.

From Barron's • Apr. 10, 2026

The seemingly limitless proliferation of cases in which lawyers have been caught letting fictitious AI-generated legal citations contaminate their briefs continues to amaze.

From Los Angeles Times • Mar. 27, 2026

We’re still waiting for the 15-hour workweek and for people to start retiring by 40 thanks to the proliferation of computers, as some predicted in the 1970s.

From The Wall Street Journal • Mar. 24, 2026

It signaled the commencement of their almost delirious proliferation.

From "The Milagro Beanfield War" by John Nichols