Chess \Chess\, n. (Bot.) A species of brome grass ({Bromus secalinus}) which is a troublesome weed in wheat fields, and is often erroneously regarded as degenerate or changed wheat; it bears a very slight resemblance to oats, and if reaped and ground up with wheat, so as to be used for food, is said to produce narcotic effects; -- called also {cheat} and {Willard's bromus}. [U. S.] [1913 Webster] Note: Other species of brome grass are called {upright chess}, {soft chess}, etc. [1913 Webster]