quick grass vs couch grass

quick grass and couch grass both are nouns.

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

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

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

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

quick grass (noun)	couch 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