noun
movement to defend the constitution
Refers to organized efforts, especially in Japanese political history, to protect the constitution from perceived threats or revisions.
戦前の護憲運動は、立憲政治を守ろうとする市民の声だった。
The prewar movement to defend the constitution was the voice of citizens trying to protect constitutional government.
Compound of 護憲 (goken, 'protect the constitution') and 運動 (undō, 'movement').