The Collaborative International Dictionary
doub grass
Doob grass \Doob" grass`\ [Hind. d?b.] (Bot.) A perennial, creeping grass ( Cynodon dactylon), highly prized, in Hindostan, as food for cattle, and acclimated in the United States. [Written also doub grass.]
Wiktionary
doub grass
n. (alternative form of doob grass English)