Either of two important medieval English parliaments, that of 1295 in the reign of Edward I, and (more usually) that of 1397, in the reign of Richard II.
Origin
Late Middle English; earliest use found in Brut.
Definition of great Parliament in US English:
great Parliament
noun
Either of two important medieval English parliaments, that of 1295 in the reign of Edward I, and (more usually) that of 1397, in the reign of Richard II.