con·sti·tu·tion·al·ism /-ʃ(ə)nəˌlɪzəm/
  立憲
  Con·sti·tu·tion·al·ism n. The theory, principles, or authority of constitutional government; attachment or adherence to a constitution or constitutional government.
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  constitutionalism
       n 1: a constitutional system of government (usually with a
            written constitution)
       2: advocacy of a system of government according to
          constitutional principles