What does the word alum mean?

Usage examples for alum

  1. I made another and larger one of stout drilling, soaked in lime- water and alum; and this was all that could be asked when put up properly on a frame. – Woodcraft by George W. Sears
  2. 12 Alum and its Sulphates............ – The Dyeing of Woollen Fabrics by Franklin Beech
  3. Pursuing our journey, at two miles above the falls we crossed a small stream which we named " Alum" creek, as it is strongly impregnated with alum. – The Discovery of Yellowstone Park by Nathaniel Pitt Langford