from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A sequence of characters, different from a password, that is used as identification and is required when logging on to a multiuser computer system, LAN, bulletin board system, or online service. Also called user ID.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A person's identification on an individual computer system.
user + name (Wiktionary)