heathland vs wasteland

heathland and wasteland both are nouns.

Word	Noun	Adjective	Verb	Adverb
heathland	Yes	No	No	No
wasteland	Yes	No	No	No

As nouns, wasteland is a hypernym of heathland; that is, wasteland is a word with a broader meaning than heathland:

heathland: a tract of level wasteland; uncultivated land with sandy soil and scrubby vegetation
wasteland: an uninhabited wilderness that is worthless for cultivation

Other hypernyms of heathland include barren, waste.

heathland (noun)	wasteland (noun)
a tract of level wasteland; uncultivated land with sandy soil and scrubby vegetation	an uninhabited wilderness that is worthless for cultivation