### Clue: For example, x and y across primarily, the other going vertically? (4)
### Answer: AXES 
 ### Explanation: Definition: For example, x and y
Definition can be read &lit given that the primary/first x-axis goes across and the other y-axis goes vertically
 first letter/"primarily" of **A**[cross] + **SEX**="the other" reversed/"going vertically"