from the GNU version of the Collaborative International Dictionary of English
- n. a hard, brittle alloy used for making the reflectors of telescopes and other instruments, usually consisting of copper and tin in various proportions, one of the best being that in which there are 126.4 parts of copper to 58.9 parts of tin, with sometimes a small proportion of arsenic, antimony, or zinc added to improve the whiteness.
from The Century Dictionary and Cyclopedia
- n. See speculum, 2.
Sorry, no etymologies found.