A forearc basin is a sedimentary basin located between a subduction zone trench and the associated volcanic arc. These basins accumulate sediments eroded from the volcanic arc and the overriding plate, and they play a crucial role in understanding subduction processes, sedimentary environments, and the tectonic evolution of convergent margins.
Reference: Ingersoll, R. V. (1979). Evolution of the Late Cretaceous Forearc Basin, Northern and Central California. Geological Society of America Bulletin.