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

The Kremlin wants the election — the first since the start of the full-scale invasion in 2022 — to underline public support for the war and give a veneer of legitimacy to its action. — ABC News, 17 Sep. 2026

And through its narrative, Maechler also underlines the need for protecting our nature. — Kevin Giraud, Variety, 16 Sep. 2026

Noun

Don’t write in, highlight, underline, or otherwise mark up a library book. — Kait Hanson, Southern Living, 17 Sep. 2026

So there is such a powerful underline of her character, this sort of fierce rebel constantly wanting to find out the truth, constantly aware of her surroundings, aware of everything. — Hunter Ingram, Variety, 4 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