There isn't a single term for the "lit shape of the moon." Instead, we use different terms based on the phase of the moon:

* New Moon: Invisible, as the sunlit side faces away from Earth.

* Waxing Crescent: A thin sliver of the moon is visible, growing larger each day.

* First Quarter: Half of the moon is illuminated, appearing as a half-circle.

* Waxing Gibbous: More than half of the moon is illuminated, growing larger each day.

* Full Moon: The entire face of the moon is illuminated.

* Waning Gibbous: More than half of the moon is illuminated, getting smaller each day.

* Last Quarter: Half of the moon is illuminated, appearing as a half-circle.

* Waning Crescent: A thin sliver of the moon is visible, getting smaller each day.

Therefore, the "lit shape of the moon" is determined by its current phase, which is a more accurate way to describe it.