'Beach grass' definitions:

Definition of 'beach grass'

noun

Tough grasses with strong roots that can grow on exposed sandy shores

From: GCIDE

Beach \Beach\ (b[=e]ch), n.; pl. Beaches (-[e^]z). [Cf. Sw. backe hill, Dan. bakke, Icel. bakki hill, bank. Cf. Bank.]
1. Pebbles, collectively; shingle. [1913 Webster]
2. The shore of the sea, or of a lake, which is washed by the waves; especially, a sandy or pebbly shore; the strand. [1913 Webster]
Beach flea (Zool.), the common name of many species of amphipod Crustacea, of the family Orchestid[ae], 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. [1913 Webster]