What does "username" mean?

A name or string of characters used as a person's identification on an individual computer system.

What is a synonym for "username"?

Common synonyms include: account name, handle, handles, login, login name, monickers.

noun

noun ·Rare ·Advanced level

Noun

1
A name or string of characters used as a person's identification on an individual computer system.
"His username and password on his Apple PC is VolvestarcXXX."

"Check that your username and password are written correctly."

From user + name.