username

noun

us·​er·​name ˈyü-zər-ˌnām 

variants or less commonly user name

plural usernames also user names

: a sequence of characters that identifies a user (such as on a computer system, website, or social media platform)

Never reuse a username and password combination. While doing so is convenient, if that combination is ever stolen from one service you use … it will expose every service you have that uses it.

—Rachel Cericola

These e-mail addresses generally look like this: "[e-mail]".

—Walter S. Mossberg

called also user ID

Examples of username in a Sentence

Recent Examples on the Web

In February 2025, the agent once again identified the remote host computer with the same username and IP address sharing files of child pornography. —Clara Harter, Los Angeles Times, 19 Mar. 2026

Save any messages, photos, usernames, and other information shared before blocking the person. —Matthew Rodriguez, CBS News, 19 Mar. 2026

Festival veterans compared notes on schedules, swapped Letterboxd usernames and debated how to navigate overlapping events. —Ana Gutierrez, Austin American Statesman, 13 Mar. 2026

Coincidentally, since Hahn joined Instagram, her username has been @motherhahn. —Dessi Gomez, Deadline, 10 Mar. 2026

Word History

First Known Use

1971, in the meaning defined above

Rhymes for username

• aspartame
• counterclaim
• overcame
• underframe
• acclaim
• aflame
• airframe
• ballgame
• became
• declaim
• defame
• disclaim

Kids Definition

username

noun

: a sequence of characters that identifies a user when logging onto a computer or website

called also user ID