As the sunlit fraction of the moon gets larger, we say the moon is waxing.

Here's why:

* Waxing: Means "growing" or "increasing." As the illuminated portion of the moon grows larger, it is said to be waxing.

* Waning: Means "decreasing" or "shrinking." When the illuminated portion of the moon gets smaller, it is said to be waning.

The moon goes through a cycle of phases, from new moon to full moon and back again. We use these terms to describe the changing appearance of the moon as it moves through its cycle.