noun
agreed constitution; pact-based constitution
A constitution established through agreement between a monarch and a representative body, as opposed to one unilaterally imposed. The French Constitution of 1830 is a classic example. This is a specialized historical/political term.
See also: 協定憲法
1830年のフランス憲法は協約憲法の一例とされる。
The French Constitution of 1830 is considered an example of an agreed constitution.
協約憲法は、君主と議会の合意に基づいて制定される。
An agreed constitution is established based on an agreement between the monarch and the parliament.
協定憲法 is a synonym also meaning a constitution established by agreement. 協約憲法 may carry a slightly stronger nuance of a formal pact or covenant, but they are largely interchangeable in historical contexts.
Compound of 協約 (agreement, pact) and 憲法 (constitution). The term is a calque from Western political science, likely coined in the Meiji period to describe constitutional models like the French Charter of 1830.