admixture, alloy -- (the state of impairing the quality or reducing the value of something)
admixture, intermixture -- (an additional ingredient that is added by mixing with the base; "the growing medium should be equal parts of sand and loam with an admixture of peat moss and cow manure"; "a large intermixture of sand")
mix, commixture, admixture, mixture, intermixture, mixing -- (the act of mixing together; "paste made by a mix of flour and water"; "the mixing of sound channels in the recording studio")