grass family vs monocot family

grass family and monocot family both are nouns.

Word	Noun	Adjective	Verb	Adverb
grass family	Yes	No	No	No
monocot family	Yes	No	No	No

As nouns, monocot family is a hypernym of grass family; that is, monocot family is a word with a broader meaning than grass family:

grass family: the grasses: chiefly herbaceous but some woody plants including cereals, bamboo, reeds, sugar cane
monocot family: family of flowering plants having a single cotyledon (embryonic leaf) in the seed

Other hypernyms of grass family include liliopsid family.

grass family (noun)	monocot family (noun)
the grasses: chiefly herbaceous but some woody plants including cereals, bamboo, reeds, sugar cane	family of flowering plants having a single cotyledon (embryonic leaf) in the seed