>I'm doing >whats known as an "Alphabet Book."
>In this "Alphabet Book,"
>I must define and give examples for geometrical terms. I
>must have 2 terms for each letter of the alphabet. However,
>I'm in a bind! I can't think of any other words that start
>with x or y! All I have for x and y are x-axis and y-axis.

Well, to "x-axis" you can add "x-coordinate", and similarly with "y". For the latter you also have "yard" - a unit of measurement, and "yaw" - the angle between the axis of a projectile and its velocity vector.