caustic potash vs potash

caustic potash and potash both are nouns.

Word	Noun	Adjective	Verb	Adverb
caustic potash	Yes	No	No	No
potash	Yes	No	No	No

As nouns, caustic potash and potash are synonyms defined as:

caustic potash and potash: a potassium compound often used in agriculture and industry

Other synonyms of caustic potash include potassium hydroxide.

caustic potash (noun)	potash (noun)
a potassium compound often used in agriculture and industry	a potassium compound often used in agriculture and industry