rainforest vs forest

rainforest and forest both are nouns.

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

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

Other hypernyms of rainforest include wood, woods.

rainforest (noun)	forest (noun)
a forest with heavy annual rainfall	the trees and other plants in a large densely wooded area
	land that is covered with trees and shrubs

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