Respuesta :

Answer:

(of the moon) have a progressively smaller part of its visible surface illuminated, so that it appears to decrease in size.

Explanation:

verb (used without object), waned, wan·ing.
to decrease in strength, intensity, etc.: Daylight waned, and night came on. Her enthusiasm for the cause is waning. to decline in power, importance, prosperity, etc.: Colonialism began to wane after World War II.