Pseudonym – A fictitious name, especially one used by an author
The badge she sewed on him (pseudonym) had a fictitious name on it.
Examples of pseudonym in a sentence
His real name was George Jones, but he wrote under the pseudonym of Brett Savage.
The undercover agent used a pseudonym to infiltrate the gang.
The world-famous pop star always checks into hotels under a pseudonym to make it more difficult for fans and the media to find her.