thoroughbrace

thor·ough·brace

(thûr′ō-brās′)
n.
One of several leather bands passed from front to back of a carriage, supporting it and serving as a spring.

thor′ough·braced′ adj.

thoroughbrace

(ˈθʌrəˌbreɪs)
n
chiefly US either of two strong leather straps upon which the body of certain types of carriage is supported
ˈthoroughˌbraced adj