Merriam-Webster's Word of the Day for May 5, 2024 is: proliferate \pruh-LIF-uh-rayt\ verb

To proliferate is to increase quickly in number or amount.

// Problems have proliferated in recent months; every day seems to present a new challenge that needs sorting out.

[See the entry >](https://www.merriam-webster.com/dictionary/proliferate)

Examples:

“Patches of scrub continue to emerge and then fall away as the canopy of young self-sown trees begins to shade them out. The beavers have created hectares of new open water and channel complexes. Deadwood is ubiquitous. Topsoil continues to grow, and fungi proliferate.” — Isabella Tree, The Book of Wilding: A Practical Guide to Rewilding, Big and Small, 2023

Did you know?

Proliferate is a [back-formation](https://www.merriam-webster.com/dictionary/back-formation) of proliferation. That means that proliferation came first (we borrowed it from French in the 1700s), and was later shortened to form the verb. Proliferation originally referred to the botanical phenomenon of some plants having buds, flowers, or other parts that are [adventitious](https://www.merriam-webster.com/dictionary/adventitious)—that is, that arise or occur sporadically or in other than the usual location (e.g. [pitch pines’](https://bit.ly/4afWl9o) ability to sprout new trees directly from their stumps after a fire). With advances in the study of biology in the 1800s, proliferation came to be used to refer to the rapid and repeated production of [cells](https://www.britannica.com/science/cell-biology) by division. That sense in turn [begat](https://www.merriam-webster.com/dictionary/beget) the verb proliferate, which eventually came to be used when anything—whether living (such as yeast) or nonliving (such as data)—quickly increases or multiplies.