Calx

1. n. Broken and refuse glass, returned to the post.
2. n. Quicklime.
3. n. The substance which remains when a metal or mineral has been subjected to calcination or combustion by heat, and which is, or may be, reduced to a fine powder.

The word meanings were obtained from OPTED(The Online Plain Text English Dictionary), which is based on “The Project Gutenberg Etext of Webster’s Unabridged Dictionary” which is in turn based on the 1913 US Webster’s Unabridged Dictionary (See Project Gutenburg), as a text file.