WordNet (r) 3.0 (2006):

witchgrass
    n 1: North American grass with slender brushy panicles; often a
         weed on cultivated land [syn: witchgrass, witch grass,
         old witchgrass, old witch grass, tumble grass,
         Panicum capillare]
    2: European grass spreading rapidly by creeping rhizomes;
       naturalized in North America as a weed [syn: dog grass,
       couch grass, quackgrass, quack grass, quick grass,
       witch grass, witchgrass, Agropyron repens]