French rye vs false oat

French rye and false oat both are nouns.

Word	Noun	Adjective	Verb	Adverb
French rye	Yes	No	No	No
false oat	Yes	No	No	No

As nouns, French rye and false oat are synonyms defined as:

French rye and false oat: coarse perennial Eurasian grass resembling oat; found on roadside verges and rough grassland and in hay meadows; introduced in North America for forage

Other synonyms of French rye include Arrhenatherum elatius, evergreen grass, tall meadow grass, tall oat grass.

French rye (noun)	false oat (noun)
coarse perennial Eurasian grass resembling oat; found on roadside verges and rough grassland and in hay meadows; introduced in North America for forage	coarse perennial Eurasian grass resembling oat; found on roadside verges and rough grassland and in hay meadows; introduced in North America for forage