tumble grass vs witch grass

tumble grass and witch grass both are nouns.

Word	Noun	Adjective	Verb	Adverb
tumble grass	Yes	No	No	No
witch grass	Yes	No	No	No

As nouns, tumble grass and witch grass are synonyms defined as:

tumble grass and witch grass: North American grass with slender brushy panicles; often a weed on cultivated land

Other synonyms of tumble grass include old witch grass, old witchgrass, Panicum capillare, witchgrass.

tumble grass (noun)	witch grass (noun)
North American grass with slender brushy panicles; often a weed on cultivated land	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