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

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

The new study from the Cook County Treasurer's office underlines growing concerns about the impact the bill could have on the county's property tax base and overall fiscal health. —Adam Harrington, CBS News, 27 May 2026

The agreement underlines Hollywood’s growing embrace of AI technology. —Jake Kanter, Deadline, 27 May 2026

Noun

After a season of upheaval with four head coaches, plus a run to the Europa League semi-finals, the fact that survival is assured with two games to spare underlines the quality of the job Pereira has done. —Paul Taylor, New York Times, 11 May 2026

The last two highlight lines alter the way Vim highlights matching parentheses by changing the highlight method to an underline instead of a big full-height cursor-emulating block. —Lee Hutchinson, ArsTechnica, 6 May 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