A homogeneous mixture or solid solution of two or more metals, the atoms of one replacing or occupying interstitial positions between the atoms of the other: Brass is an alloy of zinc and copper. A mixture; an amalgam: "Television news has . . . always been an alloy of journalism and show business\u201d ( Bill Moyers). The relative degree of mixture with a base metal; fineness. Something added that lowers value or purity. To combine (metals) to form an alloy. To combine; mix: idealism that was alloyed with political skill. To debase by the addition of an inferior element.