A more thorough explanation:

ALIUD

Aliud (ay-lee-əd) is a Latin word that means "something else" or "another thing."

• "I don't want this book, I want aliud to read."
• "I asked for a hamburger, but they gave me aliud instead."

These examples show how aliud is used to refer to something different or alternative to what was originally expected or desired. In the first example, the person wants something else to read instead of the book they were offered. In the second example, the person received something other than the hamburger they ordered.