Definitions
1.verbTo progressively lose its splendor, value, ardor, power, intensity etc.; to decline.
2.verbSaid of light that dims or diminishes in strength.
3.verbSaid of the Moon as it passes through the phases of its monthly cycle where its surface is less and less visible.
4.verbSaid of a time period that comes to an end.
5.verbTo decrease physically in size, amount, numbers or surface.
6.verbTo cause to decrease.
7.adjectiveBecoming weaker or smaller."his waning strength"
8.adjectiveOf the lunar phase: as it shrinks when viewed from the Earth."the waning moon"