herd's grass vs timothy

herd's grass and timothy both are nouns.

Word	Noun	Adjective	Verb	Adverb
herd's grass	Yes	No	No	No
timothy	Yes	No	No	No

As nouns, herd's grass and timothy are synonyms defined as:

herd's grass and timothy: grass with long cylindrical spikes grown in northern United States and Europe for hay

Other synonyms of herd's grass include Phleum pratense.

herd's grass (noun)	timothy (noun)
grass with long cylindrical spikes grown in northern United States and Europe for hay	a grass grown for hay
	grass with long cylindrical spikes grown in northern United States and Europe for hay