grass (n.) Look up grass at
Old English græs, gærs "herb, plant, grass," from Proto-Germanic grasan (cognates: Old Norse, Old Saxon, Dutch, Old High German, German, Gothic gras, Swedish gräs), from PIE *ghros- "young shoot, sprout," from root *ghre- "to grow, become green" (related to grow and green, but not to Latin gramen).

As a color name (especially grass-green, Old English græsgrene) by c. 1300. Sense of "marijuana" is recorded by 1932, American English. The grass skirt worn by people native to tropical regions is mentioned by 1874; the warning to keep off the grass by 1843 (in New York City's Central Park). Grass-fed of cattle, etc., (opposed to stall-fed) is from 1774.