potassium hydrogen tartrate vs cream of tartar

potassium hydrogen tartrate and cream of tartar both are nouns.

Word	Noun	Adjective	Verb	Adverb
potassium hydrogen tartrate	Yes	No	No	No
cream of tartar	Yes	No	No	No

As nouns, potassium hydrogen tartrate and cream of tartar are synonyms defined as:

potassium hydrogen tartrate and cream of tartar: a salt used especially in baking powder

Other synonyms of potassium hydrogen tartrate include potassium bitartrate, tartar.

potassium hydrogen tartrate (noun)	cream of tartar (noun)
a salt used especially in baking powder	a salt used especially in baking powder