a name that has been assumed temporarily
"The detective noticed that the suspect was operating under an alias while evading arrest."
Another name; an assumed name.
"The hacker entered the website using a fake identity, but his real alias was revealed when he forgot to change his browser history."
In plain English: An alias is another name someone uses to hide their real identity.
"The hacker logged into the server under an alias to hide his identity."
To assign an additional name to an entity, often a more user-friendly one.
"The database administrator created an alias for the complex table name so that users could reference it easily in their queries."
In plain English: To alias something means to pretend it is someone else by using another name instead of your real one.
"The hacker tried to alias his identity so no one would recognize him from previous crimes."
as known or named at another time or place
"Mr. Smith, alias Mr. Lafayette"
Otherwise; at another time; in other circumstances; otherwise called.
"The suspect was known to police by his real name, but also went by several aliases during his criminal career."
In plain English: To alias means to pretend to be someone else by using a different name.
"She waited for hours under an alias before finally spotting her friend in the crowd."
Usage: Do not use "alias" as an adverb meaning "otherwise," since this usage is archaic and rarely understood today. Instead, rely on the noun form to describe a person's alternate identity or keep it strictly for technical contexts where software assigns alternative names to entities.
The word comes from the Latin phrase alias, which originally meant "at another time," "elsewhere," or "otherwise." It entered English with this general sense of referring to something different or alternative.