# underline

> English word · Noun · IPA /ˈʌndɚˌlaɪn/ · frequency rank #29,874

## Definitions
1. A line placed underneath a piece of text in order to provide emphasis or to indicate that it should be viewed in italics or (in electronic documents) that it acts as a hyperlink.
2. The character _.
3. An announcement of a theatrical performance to follow, placed in an advertisement for the current one.
4. A caption beneath a photograph (which may have more than one line of text).

## Etymology
From under- + line.

## Easily confused with
- **underpin** (https://plainspell.com/en/vs/underline-vs-underpin)
- **undermine** (https://plainspell.com/en/vs/underline-vs-undermine)
- **underside** (https://plainspell.com/en/vs/underline-vs-underside)
- **undertone** (https://plainspell.com/en/vs/underline-vs-undertone)
- **underlying** (https://plainspell.com/en/vs/underline-vs-underlying)
- **underlined** (https://plainspell.com/en/vs/underline-vs-underlined)
- **underlie** (https://plainspell.com/en/vs/underlie-vs-underline)

## Common misspellings (13)
`nuderline`, `udnerline`, `undderline`, `undelrine`, `underilne`, `underlien`, `underlinne`, `underlline`, `underlnie`, `underrline`, `undreline`, `unedrline`, `unnderline`

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/underline