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

In Dorian Gray, the approach underlined Dorian’s split personalities, as well as the way in which the young man was a construct of the various conflicting influences upon him. —Demetrios Matheou, HollywoodReporter, 18 Feb. 2026

With such a tight budget, this particular choice had a profound impact on the cast, underlined Coesens. —Kevin Giraud, Variety, 18 Feb. 2026

Noun

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

Reports that major banks are considering product responses (new cards structured to comply) underline how quickly the economics of lending can be reframed by policy—even if implementation is uncertain. —Zennon Kapron, Forbes.com, 29 Jan. 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