Johnson grass \John"son grass`\ [Named after W. Johnson of Alabama, who planted it about 1840-1845.] (Bot.) A tall perennial grass ({Sorghum Halepense}), valuable in the Southern and Western States for pasture and hay. The rootstocks are large and juicy and are eagerly sought by swine. Called also {Cuba grass}, {Means grass}, {Evergreen millet}, and {Arabian millet}. [1913 Webster]