potassium nitrate vs saltpetre

potassium nitrate and saltpetre both are nouns.

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

As nouns, potassium nitrate and saltpetre are synonyms defined as:

potassium nitrate and saltpetre: (KNO3) used especially as a fertilizer and explosive

Other synonyms of potassium nitrate include niter, nitre, saltpeter.

potassium nitrate (noun)	saltpetre (noun)
(KNO3) used especially as a fertilizer and explosive	(KNO3) used especially as a fertilizer and explosive