Any of several marine grasses of the genus Phyllospadix (family Zosteraceae), having thickened rootstocks and slender stems, and growing underwater on rocky shores in temperate regions.
Origin
1920s.
Definition of surf-grass in US English:
surf-grass
noun
Any of several marine grasses of the genus Phyllospadix (family Zosteraceae), having thickened rootstocks and slender stems, and growing underwater on rocky shores in temperate regions.