What is "forearc"

n. (context geology English) A region of raised rock debris which forms between the subduction zone and any associated volcano or volcanic chain.

A forearc is the region between an oceanic trench and the associated volcanic arc. As such, forearc regions are found at convergent margins, and include any accretionary wedge and forearc basin that may be present. Due to tectonic stresses as one tectonic plate rides over another, forearc regions are sources for great thrust earthquakes