user ID
compound.compound. a unique name or number that identifies you when you log into a computer system or website. You usually need this along with a password to access your account.
compound. a unique sequence of characters used to identify a specific person during the authentication process on a computer system or network. Often paired with a password or biometric data to grant access.
Please enter your user ID and password to log in.
If you forget your user ID, the system can email it to the address you provided during registration.
Security protocols often dictate that a user ID should not contain personally identifiable information to prevent unauthorized actors from guessing account credentials through social engineering.
A compound formed from the noun user and the initialism ID, which stands for identification. It follows the established linguistic pattern of combining a functional role with a shortened form of identity documentation.
Often written as 'userID' in technical documentation or 'username' in casual web contexts.