undershoe

plural undershoes

1. A covering for the foot, sturdier than a sock, worn under the outer shoes.

   The rubber overshoe is made to protect only the ball of the foot or is provided with an opening through which the heel of the undershoe projects.

   1900, Official Gazette of the United States Patent Office, page 2576

   1 more example

   Then he inserted the blade of his knife under the top of Peary's sealskin boots. He ripped the boots from both feet and gently removed the rabbitskin undershoes.

   1973, Dennis Rawlins, Peary at the North Pole: Fact Or Fiction?, page 43