timothy vs herd's grass

timothy and herd's grass both are nouns.

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

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

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

Other synonyms of timothy include Phleum pratense.

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