1. The question asks about the meaning of the variable $x$ given that $A = Z$ and $B = Y$. 2. However, from the statement alone, there is no direct information or equation linking $x$ to $A$, $B$, $Z$, or $Y$. 3. To determine what $x$ means, more context or an equation including $x$ is necessary. 4. Without that, $x$ is just a variable whose meaning depends on additional information or relationships. 5. Please provide more details or an equation involving $x$ for a clearer explanation.