# underline vs underlying

> English confusable word pair

## The two words

### underline
*noun · IPA /ˈʌndɚˌlaɪn/ · frequency rank #29,874*
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.

### underlying
*adjective · frequency rank #5,464*
lying underneath

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