potassium nitrate vs niter

potassium nitrate and niter both are nouns.

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

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

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

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

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