wasteland vs heath

wasteland and heath both are nouns.

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

As nouns, heath is a hyponym of wasteland; that is, heath is a word with a more specific, narrower meaning than wasteland:

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

Other hyponyms of wasteland include heathland.

wasteland (noun)	heath (noun)
an uninhabited wilderness that is worthless for cultivation	a tract of level wasteland; uncultivated land with sandy soil and scrubby vegetation
	a low evergreen shrub of the family Ericaceae; has small bell-shaped pink or purple flowers