deepen

American

[dee-puhn] / ˈdi pən /

verb (used with or without object)

to make or become deep or deeper.

Larger ships will be able to navigate the river after the main channel is deepened. The shadows deepened toward late afternoon.
Meteorology. to decrease in atmospheric pressure.

a deepening cyclone.

deepen British

/ ˈdiːpən /

verb

to make or become deep, deeper, or more intense

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Word Forms

deepener noun
deepeningly adverb
overdeepen verb (used with object)
undeepened adjective

Etymology

Origin of deepen

First recorded in 1595–1605; deep + -en ¹

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

The trip is Takaichi's first to Vietnam since becoming prime minister in October and she aims to deepen bilateral cooperation on energy security, supply chain resilience and technological innovation, according to Vietnamese state media reports.

From Barron's • May 2, 2026

Demand losses could deepen to around 5.5 million barrels per day in May.

From MarketWatch • Apr. 30, 2026

These results deepen scientists' understanding of superconductors and other quantum materials made of fermions.

From Science Daily • Apr. 27, 2026

Recent changes to a foreign worker program threaten to deepen the wound.

From Los Angeles Times • Apr. 22, 2026

To deepen the weight on my back was the disapproval of my teammates, who were less than forgiving when I lost a point or didn’t measure up to their expectations.

From "Proud" by Ibtihaj Muhammad

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023