Meaning: Gradually decrease in value or intensity (vigor, power, or extent); become weaker.
Synonyms: Decline, diminish, dwindle, shrink, tail off, ebb, fade (away), lessen, peter out, fall off, recede, slump, flag, weaken, give way, wither, crumble, evaporate, disintegrate, die out, evanesce.
In Hindi: क्षय, फीका, घटता हुआ.
Use: When the package arrived in the mail, my enthusiasm waned.
Since sales have started to wane, the store is in danger of becoming unprofitable.