nitre vs saltpetre

nitre and saltpetre both are nouns.

Word	Noun	Adjective	Verb	Adverb
nitre	Yes	No	No	No
saltpetre	Yes	No	No	No

As nouns, nitre and saltpetre are synonyms defined as:

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

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

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