defoliant vs chemical compound

defoliant and chemical compound both are nouns.

Word	Noun	Adjective	Verb	Adverb
defoliant	Yes	No	No	No
chemical compound	Yes	No	No	No

As nouns, chemical compound is a hypernym of defoliant; that is, chemical compound is a word with a broader meaning than defoliant:

defoliant: a chemical that is sprayed on plants and causes their leaves to fall off
chemical compound: (chemistry) a substance formed by chemical union of two or more elements or ingredients in definite proportion by weight

Other hypernyms of defoliant include compound.

defoliant (noun)	chemical compound (noun)
a chemical that is sprayed on plants and causes their leaves to fall off	(chemistry) a substance formed by chemical union of two or more elements or ingredients in definite proportion by weight