cow pasture vs grazing land

cow pasture and grazing land both are nouns.

Word	Noun	Adjective	Verb	Adverb
cow pasture	Yes	No	No	No
grazing land	Yes	No	No	No

As nouns, grazing land is a hypernym of cow pasture; that is, grazing land is a word with a broader meaning than cow pasture:

cow pasture: a pasture for cows
grazing land: a field covered with grass or herbage and suitable for grazing by livestock

Other hypernyms of cow pasture include lea, ley, pasture, pasture land, pastureland.

cow pasture (noun)	grazing land (noun)
a pasture for cows	a field covered with grass or herbage and suitable for grazing by livestock