top executive vs big businessman

top executive and big businessman both are nouns.

Word	Noun	Adjective	Verb	Adverb
top executive	Yes	No	No	No
big businessman	Yes	No	No	No

As nouns, top executive and big businessman are synonyms defined as:

top executive and big businessman: a very wealthy or powerful businessman

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

top executive (noun)	big businessman (noun)
a very wealthy or powerful businessman	a very wealthy or powerful businessman