ədˈmɪkstʃə(ɹ) ˈæ.lɔɪ əˈlɔɪ dɪˈbeɪs ˈmɛtəl make an alloy of lower in value by increasing the base-metal content the state of impairing the quality or reducing the value of something a mixture containing two or more metallic elements or metallic and nonmetallic elements usually fused together or dissolving into each other when molten brass is an alloy of zinc and copper