witchgrass vs quick grass

witchgrass and quick grass both are nouns.

Word	Noun	Adjective	Verb	Adverb
witchgrass	Yes	No	No	No
quick grass	Yes	No	No	No

As nouns, witchgrass and quick grass are synonyms defined as:

witchgrass and quick grass: European grass spreading rapidly by creeping rhizomes; naturalized in North America as a weed

Other synonyms of witchgrass include Agropyron repens, couch grass, dog grass, quack grass, quackgrass, witch grass.

witchgrass (noun)	quick grass (noun)
North American grass with slender brushy panicles; often a weed on cultivated land	European grass spreading rapidly by creeping rhizomes; naturalized in North America as a weed
European grass spreading rapidly by creeping rhizomes; naturalized in North America as a weed