toxic waste site vs waste-yard

toxic waste site and waste-yard both are nouns.

Word	Noun	Adjective	Verb	Adverb
toxic waste site	Yes	No	No	No
waste-yard	Yes	No	No	No

As nouns, waste-yard is a hypernym of toxic waste site; that is, waste-yard is a word with a broader meaning than toxic waste site:

toxic waste site: a location where toxic wastes can be or have been disposed of (often illegally)
waste-yard: a piece of land where waste materials are dumped

Other hypernyms of toxic waste site include dump, dumpsite, garbage dump, rubbish dump, trash dump, wasteyard.

toxic waste site (noun)	waste-yard (noun)
a location where toxic wastes can be or have been disposed of (often illegally)	a piece of land where waste materials are dumped