(spĕnˈsə-rĭzˌəm) also Spen·ce·ri·an·ism (spĕn-sîrˈē-ə-nĭzˌəm)
noun The system of thought developed by Herbert Spencer, setting forth the idea that evolution is the passage from the simple, indefinite, and incoherent to the complex, definite, and coherent.