virgin forest vs forest

virgin forest and forest both are nouns.

Word	Noun	Adjective	Verb	Adverb
virgin forest	Yes	No	No	No
forest	Yes	No	Yes	No

As nouns, forest is a hypernym of virgin forest; that is, forest is a word with a broader meaning than virgin forest:

virgin forest: forest or woodland having a mature or overly mature ecosystem more or less uninfluenced by human activity
forest: the trees and other plants in a large densely wooded area

Other hypernyms of virgin forest include wood, woods.

virgin forest (noun)	forest (noun)
forest or woodland having a mature or overly mature ecosystem more or less uninfluenced by human activity	the trees and other plants in a large densely wooded area
	land that is covered with trees and shrubs

virgin forest (verb)	forest (verb)
	establish a forest on previously unforested land