big businessman vs baron

big businessman and baron both are nouns.

Word	Noun	Adjective	Verb	Adverb
big businessman	Yes	No	No	No
baron	Yes	No	No	No

As nouns, big businessman and baron are synonyms defined as:

Other synonyms of big businessman include business leader, king, magnate, mogul, power, top executive, tycoon.

big businessman (noun)	baron (noun)
a very wealthy or powerful businessman	a British peer of the lowest rank
	a very wealthy or powerful businessman
	a nobleman (in various countries) of varying rank