single-footer

To refer to a trotter as a thoroughbred is to suffer social ostracism, and to obfuscate a side-wheeler with a single-footer is proof of degeneracy.

Little Journeys To the Homes of the Great Hubbard, Elbert, 1856-1915 1916

He drew nearer and nearer, and as he came out on the wide patch of moonlit snow, he pulled the single-footer down to a walk and halted him and began fumbling in the right-hand side of the saddlebags that draped his horse's shoulder.

The Escape of Mr. Trimm His Plight and other Plights 1910

And now it was a "single-footer" coming, the only one at Sandy.

An Apache Princess A Tale of the Indian Frontier Charles King 1888

a side-wheeler with a single-footer is proof of degeneracy.

Little Journeys to the Homes of the Great - Volume 03 Little Journeys to the Homes of American Statesmen Elbert Hubbard 1885

Hart's single-footer in a day or two, Miss Angela, and then -- "

An Apache Princess A Tale of the Indian Frontier Charles King 1888