v. & n.
v.intr. 1 (of the moon) decrease in apparent size after the full moon (cf. WAX(2)). 2 decrease in power, vigour, importance, brilliance, size, etc.; decline.
n. 1 the process of waning. 2 a defect of a plank etc. that lacks square corners. on the wane waning; declining. waney adj. (in sense 2 of n.).
[ OE wanian lessen f. Gmc ]