When less of the moon is visible, it's called a waning crescent or waning gibbous, depending on how much of it is visible.

Here's a breakdown:

* Waning Crescent: The moon appears as a thin sliver, getting smaller each night. It's located in the morning sky.

* Waning Gibbous: The moon is more than half illuminated but less than full, with the lit portion decreasing each night. It's visible in the afternoon and evening sky.

The term "waning" means decreasing, referring to the amount of the illuminated portion of the moon we see.