Beach flea (Zoöl.), the common name of many species of amphipod Crustacea, of the family Orchestidæ, living on the sea beaches, and leaping like fleas. -- Beach grass (Bot.), a coarse grass (Ammophila arundinacea), growing on the sandy shores of lakes and seas, which, by its interlaced running rootstocks, binds the sand together, and resists the encroachment of the waves. -- Beach wagon, a light open wagon with two or more seats. -- Raised beach, an accumulation of water-worn stones, gravel, sand, and other shore deposits, above the present level of wave action, whether actually raised by elevation of the coast, as in Norway, or left by the receding waters, as in many lake and river regions.