potassium nitrate vs nitrate

potassium nitrate and nitrate both are nouns.

Word	Noun	Adjective	Verb	Adverb
potassium nitrate	Yes	No	No	No
nitrate	Yes	No	Yes	No

As nouns, nitrate is a hypernym of potassium nitrate; that is, nitrate is a word with a broader meaning than potassium nitrate:

potassium nitrate: (KNO3) used especially as a fertilizer and explosive
nitrate: any compound containing the nitrate group (such as a salt or ester of nitric acid)

potassium nitrate (noun)	nitrate (noun)
(KNO3) used especially as a fertilizer and explosive	any compound containing the nitrate group (such as a salt or ester of nitric acid)

potassium nitrate (verb)	nitrate (verb)
	treat with nitric acid, so as to change an organic compound into a nitrate