backwashThe movement of seawater down a beach after a wave has broken on it. An incoming wave is taken up the beach by the swash; backwash takes it back again. On a hard beach the backwash is on the surface; or it may be within the shingle or sand on a softer beach. Related category GEOLOGY AND PLANETARY SCIENCEAlso on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History |