underline

American  

[uhn-der-lahyn, uhn-der-lahyn, uhn-der-lahyn] / ˈʌn dərˌlaɪn, ˌʌn dərˈlaɪn, ˈʌn dərˌlaɪn /

verb (used with object)

underlined, underlining

1. to mark with a line or lines underneath; underscore.

2. to indicate the importance of; emphasize, as by stressing or italicizing.

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noun

1. Printing. a caption under an illustration.

2. a line drawn under something; an underscore.

underline British  

verb

1. to put a line under

2. to state forcibly; emphasize or reinforce

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noun

1. a line underneath, esp under written matter

Other Word Forms

• underlineation noun
• underliner noun
• underlining noun

Etymology

Origin of underline

First recorded in 1715–25; under- + line ¹

Example Sentences

His comments underline Beijing's concerns that weak domestic consumption makes the country too reliant on exports for growth, as well as highlighting its ambitions to upgrade the country's manufacturing industries.

From BBC • Mar. 4, 2026

Either choice would underline the FOMC’s independence from the president in a most striking manner.

From Barron's • Feb. 25, 2026

And a regional Super Bowl commercial from Kellogg’s Raisin Bran is set to underline the importance of dietary fiber.

From The Wall Street Journal • Feb. 6, 2026

The results underline how widespread microplastic pollution has become, reaching even some of the most remote marine environments on Earth.

From Science Daily • Feb. 3, 2026

I trust I need hardly underline the extent of the discomfort I suffered tonight on account of the unfortunate misunder-standing concerning my person.

From "The Remains of the Day" by Kazuo Ishiguro

Related Words

• accentuate
• highlight
• indicate
• point up
• stress
• underscore