Wane : (of a state or feeling) decrease in vigour or extent; become weaker.Swell : (especially of a part of the body) become larger or rounder in size, typically as a result of an accumulation of fluid.Prosper : succeed in material terms; be financially successful.Fatten : make or become fat or fatter.Widen : make or become wider.Antonym of Wane is Prosper