dog grass vs quackgrass

dog grass and quackgrass both are nouns.

Word	Noun	Adjective	Verb	Adverb
dog grass	Yes	No	No	No
quackgrass	Yes	No	No	No

As nouns, dog grass and quackgrass are synonyms defined as:

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

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

dog grass (noun)	quackgrass (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