Constitutional Government
noun
A constitution government is a constitutional government.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
彼女は、タイの憲政史上最も若い首相です。
She is the youngest prime minister in Thailand's constitutional history.
私は日本と中国の憲政を比較する研究をしています。
I am doing a study comparing the constitutional systems of Japan and China.
憲法によって行う政治のことを「憲政」や「立憲政治」といいます。
Politics conducted by means of a constitution is called "kensei" or "rikken-seiji."