quack grass vs quick grass

quack grass and quick grass both are nouns.

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

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

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

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

quack grass (noun)	quick grass (noun)
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