A thief's takings are called swag:
illustration by mcol
and so, in Australia and New Zealand, is the pack carried by a travelling workman.
A water-filled depression cause by subsidence over a mine is a swag, and so is a deliberately droopy bit of curtain:
these, amazingly, were carved in wood by the furniture company Chippendale. Photo by Ivorpics
A festoon of flowers is a swag, too:
painting by Gaspar Peeter Verbruggen the Younger
So what's the connection between all those?
Spot the Frippet: swag. This word appeared in the 1600s, perhaps from Scandinavia. The Norwegian svagga means to sway.