caustic potash vs potassium hydroxide

caustic potash and potassium hydroxide both are nouns.

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

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

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

Other synonyms of caustic potash include potash.

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