witch grass vs tumble grass

witch grass and tumble grass both are nouns.

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

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

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

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

witch grass (noun)	tumble 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