D defs.my
Entry 1 sense Webster, 1913

Billon

/bĭl'-ən/ · Bil·lon · IPA /bˈɪlən/
01 n. An alloy of gold and silver with a large proportion of copper or other base metal, used in coinage.
  1. 1.
    An alloy of gold and silver with a large proportion of copper or other base metal, used in coinage.