The Collaborative International Dictionary
Sway-backed
Sway-backed \Sway"-backed`\, a. Having the back hollow or sagged, whether naturally or as the result of injury or weakness; -- said of horses and other animals.
Douglas Harper's Etymology Dictionary
Wiktionary
sway-backed
a. (alternative spelling of swaybacked English)
Usage examples of "sway-backed".
These rambling, sway-backed tunnels are very attractive things, with their alcoved outlooks upon the lovely and inspiriting water.
After World War II, Eldred had laid out some of his hard-earned cash to buy Kenny a shaggy, sway-backed pony, which the Stouts had kept tethered to a chinaberry tree in the backyard.