What does "alloy" mean?

Alloy: The quality, or comparative purity, of gold or silver; fineness.

Additional senses

  1. 2.A baser metal mixed with a finer. Fine silver is silver without the mixture of any baser metal. Alloy is baser metal mixed with it. Locke.
  2. 3.Admixture of anything which lessens the value or detracts from; as, no happiness is without alloy. "Pure English without Latin alloy." F. Harrison.
  3. 4.To reduce the purity of by mixing with a less valuable substance; as, to alloy gold with silver or copper, or silver with copper.
  4. 5.To mix, as metals, so as to form a compound.
  5. 6.To abate, impair, or debase by mixture; to allay; as, to alloy pleasure with misfortunes.
  6. 7.To form a metallic compound. Gold and iron alloy with ease. Ure.

Sources