rubber diaper

plural rubber diapers

1. datedAn undergarment worn over a diaper to prevent leakage through the fabric, similar to plastic pants but made from rubber.

   One rubber diaper, to be used as seldom as possible—only for brief periods when visiting or travelling; it is worn over the cloth diaper and should not have elastic at the top or around the legs.

   1951, Lewis Copeland, Lawrence W. Lamm, The Everyday Reference Library, Unicorn Publishers, page 406

   1 more example

   Imagine before you now the dear little infant, with clothes wet around the hips, sometimes even up to the neck, not only with urine but stained by feces, freely giving off an offensive urinous and fecal odor combined with a gangrenous fetor arising from decomposition, not desiccation, of the cord. All this is not infrequently covered with a water-proof rubber diaper to protect the bed, notwithstanding the risk of the babe's life.

   1897, A. C. Wentz, “The Umbilical Cord”, in Adolf Kœnig, editor, Pennsylvania Medical Journal, volume XXVIII, Murdoch-Kerr Press, page 13