Synonyms

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.

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

From Science Daily • Apr. 27, 2026

They worshipped in a two-bedroom apartment while the group raised money to build a more permanent mosque—a spiritual home that would deepen their roots in their hometown.

From Slate • Apr. 19, 2026

Meanwhile, the humanitarian crisis across Lebanon continues to deepen.

From BBC • Apr. 15, 2026

The recent plan to acquire a 45% stake in Zhongheng Electric will likely further deepen vertical integration across the energy-storage value chain, they add.

From The Wall Street Journal • Apr. 14, 2026

When they see me, their scowls only deepen; they both straighten up.

From "Love, Hate & Other Filters" by Samira Ahmed

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