social democracy        
noun uk/ˌsəʊ.ʃəl dɪˈmɒk.rə.si/ us/ˌsoʊ.ʃəl dɪˈmɑː.krə.si/
 [ U ]社会民主主义;社会民主主义制度 
the belief that society should change from capitalism to socialism in a gradual, peaceful way; a system of government based on this belief
  [ C ]实行社会民主主义制度的国家 
a country that has this system of government