underline

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verb

un·​der·​line ˈən-dər-ˌlīn  ˌən-dər-ˈlīn 

underlined; underlining; underlines

transitive verb

1

: to mark (something, such as a word) with a line underneath

2

: to put emphasis on : stress

The incident underlines our need our need for better procedures.

3

: to show clearly or emphatically

underline

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noun

un·​der·​line ˈən-dər-ˌlīn 

1

: the outline of a quadruped's underbody

also : the ventral surface of a quadruped's body

2

: a horizontal line placed underneath something

Synonyms of underline

Verb

• emphasize
• reinforce

Examples of underline in a Sentence

Verb

His name was underlined in the book.

The accident underlines our need for better safety procedures.

Recent Examples on the Web

Verb

This year has been dominated by two global sporting events, the Olympics and the World Cup, that underline how the business of sports and those who lead it are changing culture in unprecedented ways. —Sam Jacobs, Time, 15 Apr. 2026

The point underlines the broader commercial afterlife the Goyas can generate for a film. —Emiliano De Pablos, Variety, 14 Apr. 2026

Noun

Such an extreme differential underlines how frequently Newcastle are almost donating goals to their opponents. —Chris Waugh, New York Times, 2 Mar. 2026

All of this underlines why fixing the problem of affordable housing in New York City is not so simple as freezing rents. —Michael Powell, The Atlantic, 11 Feb. 2026

Word History

First Known Use

Verb

1721, in the meaning defined at sense 1

Noun

1886, in the meaning defined at sense 1

Rhymes for underline

• acridine
• alkaline
• andesine
• anodyne
• anticline
• arginine
• asinine
• atropine
• benzidine
• borderline
• byzantine
• calamine

Kids Definition

underline

verb

un·​der·​line

ˈən-dər-ˌlīn, 

ˌən-dər-ˈlīn

1

: to draw a line under : underscore

2

: emphasize

underline

ˈən-dər-ˌlīn

noun