underline

1 of 2

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

2 of 2

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

President Donald Trump‘s appearance in Youngstown, Ohio, on Monday underlines the Mahoning Valley as a bellwether of whether Democrats can win back the white, working-class voters that have rapidly shifted away from the party in recent years. — Naomi Lim, The Washington Examiner, 14 Oct. 2026

Yet in all these success stories, Haylaz underlined that traditional entertainment companies typically create characters, build an audience and subsequently commercialize that audience through consumer products and merchandise. — Kevin Giraud, Variety, 13 Oct. 2026

Noun

But all this wry meta-ness can’t obscure the season’s dearth of original ideas, and the many cameos from beloved characters like Rickety Cricket and Artemis underline how few truly memorable new ensemble members have been added in recent seasons. — Roxana Hadadi, Vulture, 13 Oct. 2026

Don’t write in, highlight, underline, or otherwise mark up a library book. — Kait Hanson, Southern Living, 17 Sep. 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

• alkaline
• andesine
• anodyne
• anticline
• arginine
• asinine
• benzidine
• borderline
• byzantine
• calamine
• caroline
• centerline

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