Is “Waning” a Scrabble word?
Yes
WANING
Valid in at least one Scrabble dictionary
Valid in these dictionaries
SOWPODS / CSW
Scrabble UK & International
TWL / NWL
Scrabble North America
Large English Dictionary
General English word list
Meaning of Waning
/ˈweɪ.nɪŋ/
verb
1.To progressively lose its splendor, value, ardor, power, intensity etc.; to decline.
2.Said of light that dims or diminishes in strength.
3.Said of the Moon as it passes through the phases of its monthly cycle where its surface is less and less visible.
adjective
1.Becoming weaker or smaller.
“his waning strength”
2.Of the lunar phase: as it shrinks when viewed from the Earth.
“the waning moon”