As the moon appears to be getting smaller, it is said to be...?

When the moon appears to be getting smaller, it is referred to as waning. This phase occurs after the full moon when the visible portion of the moon that is illuminated by the sun decreases. During this time, the illuminated surface of the moon is moving towards the new moon phase, which is when the moon is not visible from Earth.

Waning is characterized by phases such as the waning gibbous, which comes right after a full moon, and the waning crescent, which occurs just before the new moon. This terminology is important in understanding the lunar cycle, as it helps to describe the moon's changing appearance in the night sky based on its position relative to the Earth and the sun.

The other terms provided, such as waxing, refer to the opposite process where the moon is increasing in illumination, while full and new designate specific phases where the moon is either completely illuminated or not visible, respectively.