In full rosha grass, †rosha paper grass. A South-East Asian grass, Cymbopogon martinii, from which an essential oil is obtained.
Origin
Mid 19th century. Partly from Hindi rūsā, and partly from its cognate Marathi rośẽ from Sanskrit rohiṣa, denoting the grasses, apparently lit. ‘red, reddish’ (although the semantic motivation is unclear), ultimately from the same Indo-European base as red.