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

The hilarious clip, shared on Instagram on Friday under the username @mostly_ghostly1, shows the poster lying by the edge of the bed, almost falling off of it, while her rescue pup, Mookie, sleeps right in the middle, snuggled up to her husband. —Maria Azzurra Volpe, MSNBC Newsweek, 3 Sep. 2025

That same day, Pagan sent the username and password for the shell company to Costanzo via electronic message. —Jay Weaver, Miami Herald, 29 Aug. 2025

Changing it will impact usernames across the organization. —PC Magazine, 24 Aug. 2025

In the truck, investigators found a briefcase reportedly containing a notebook with all of Reyes’s passwords and usernames. —Michelle L. Quinn, Chicago Tribune, 23 Aug. 2025

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