Noun witch grass has 2 senses

• witch grass(n = noun.plant) old witch grass, old witchgrass, panicum capillare, tumble grass, witchgrass - North American grass with slender brushy panicles; often a weed on cultivated land; Array
is a kind of panic grass

• witch grass(n = noun.plant) agropyron repens, couch grass, dog grass, quack grass, quackgrass, quick grass, witchgrass - European grass spreading rapidly by creeping rhizomes; naturalized in North America as a weed; Array
is a kind of wheat-grass, wheatgrass