Source : Webster's Revised Unabridged Dictionary (1913)

Quitch grass \Quitch" grass`\ [Properly quick grass, being
   probably so called from its vigorous growth, or from its
   tenacity of life. See {Quick}, and cf. {Couch grass}.] (Bot.)
   A perennial grass ({Agropyrum repens}) having long running
   rootstalks, by which it spreads rapidly and pertinaciously,
   and so becomes a troublesome weed. Also called {couch grass},
   {quick grass}, {quick grass}, {twitch grass}. See
   Illustration in Appendix.