deepen

verb

deep·​en ˈdē-pən 

deepened; deepening ˈdē-pə-niŋ 

ˈdēp-niŋ

transitive verb

: to make deep or deeper

intransitive verb

: to become deeper or more profound

Synonyms of deepen

• intensify
• enhance
• heighten
• strengthen

Examples of deepen in a Sentence

They deepened the river so that larger boats could sail through.

Age had deepened the lines in his face.

The water deepens toward the center of the river.

Her powerful words deepened our commitment to the cause.

The vacation together deepened their relationship with each other.

The mystery was deepened by her silence.

This class will deepen your understanding of economics.

Living in the country's capital had deepened her knowledge of politics.

Recent Examples on the Web

Prime Minister Anthony Albanese and Vietnamese President To Lam met in Canberra last month, pledging to deepen their partnership on issues like defense and trade. — Shibani Mahtani, NPR, 2 Oct. 2026

What’s more, its growth runway could widen materially as the Huntsville, Alabama, company deepens its relationships with disruptive defense innovator Anduril Industries and space-launch leader SpaceX . — Harvey Stober, CNBC, 2 Oct. 2026

Only parts of Choi’s body were recovered, deepening the mystery at the time surrounding the violent death of the prominent young socialite. — Chris Lau, CNN Money, 2 Oct. 2026

Knowledge workers can also use AI’s outputs to examine topics from multiple viewpoints, deepening their knowledge. — Monideepa Tarafdar, The Conversation, 2 Oct. 2026

Word History

First Known Use

1600, in the meaning defined at transitive sense

Rhymes for deepen

• cheapen
• marzipan

Kids Definition

deepen

verb

deep·​en ˈdē-pən 

deepened; deepening ˈdēp-(ə-)niŋ 

: to make or become deep or deeper